The title compounds, C8H14O4 and C16H26O7, are precursors to dendrimers. The strong and weak hydrogen bonds in their extended structures are described.
Keywords: crystal structure, anhydride, hydrogen bond, dioxane, carboxylic acid
Abstract
In 2,2,5-trimethyl-1,3-dioxane-5-carboxylic acid, C8H14O4, the carboxyl group occupies an equatorial position on the 1,3-dioxane ring. In the crystal, O—H⋯O hydrogen bonds form chains of molecules, which are linked into a three-dimensional network by C—H⋯O hydrogen bonds. The asymmetric unit of 2,2,5-trimethyl-1,3-dioxane-5-carboxylic anhydride, C16H26O7, consists of two independent molecules, which are linked by C—H⋯O hydrogen bonds. In the crystal, these units are connected into corrugated layers two molecules thick and parallel to the ab plane by additional C—H⋯O hydrogen bonds.
Chemical context
Dendrimers are perfectly branched, monodisperse, multivalent polymeric structures that exhibit enhanced solubility, increased reactivity and reduced dispersity compared to linear polymer analogs (Ihre et al., 1996a
▸). While there are several varieties of dendrimers, a protected monomer has been used to make most dendrimers (Buhleier et al., 1978 ▸; Tomalia et al. 1985 ▸; Hawker & Fréchet, 1992 ▸). 2,2-Bis(hydroxymethyl)propionic acid (bis-MPA) is one of the most popular (Ihre et al., 1996b
▸), useful and well-studied because of its low cost and relative ease of synthesis yielding extremely precise structures (Grayson et al., 2014 ▸), while also being biocompatible, biodegradable and extremely modular. The synthesis of these polyester-based dendrimers relies on first protecting the hydroxyl groups of the monomer and then, after an exhaustive protection of the core, complete removal of the protecting group exposing the hydroxyl groups of the next generation. To that end, the isopropyl acetal (isopropylidene/acetonide) has become one of the most commonly compounds used in the production of the monomeric unit (Stenström et al., 2016 ▸; García-Gallego et al., 2015 ▸). Anhydride-catalyzed esterification has become the preferred route of synthesis to produce these highly precise, bis-functional structures by decreasing the steps of purification and improving the efficiency of deprotection to the final poly-ol. The scope and diversity of these types of structures can be seen in the increase in publications on dendrimers and the numerous reviews published in recent years. We report here the syntheses and crystal structures of two important intermediates in our work on dendrimer syntheses, viz. 2,2,5-trimethyl-1,3-dioxane-5-carboxylic acid (C8H14O4) and 2,2,5-trimethyl-1,3-dioxane-5-carboxylic anhydride (C16H26O7).
Structural commentary
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid, I, (Fig. 1 ▸) has the methyl groups containing C6 and C8 in trans axial positions while the C7 methyl group and the carboxyl group are equatorial on the 1,3-dioxane ring, which adopts an approximate chair conformation. A puckering analysis of this conformation gave the parameters Q = 0.5540 (9) Å, θ = 176.65 (9)° and φ = 301.8 (17)°. The O2—C1—C2—C5 torsion angle of −159.88 (8)° indicates that the carboxyl group is approximately aligned with the mean plane through the 1,3-dioxane ring.
Figure 1.
Perspective view of I with 50% probability displacement ellipsoids.
The asymmetric unit of 2,2,5-trimethyl-1,3-dioxane-5-carboxylic anhydride, II, consists of two independent molecules each having an overall ‘U′ shape (Fig. 2 ▸) but differing in part by having opposite conformations in the anhydride portions. Thus, the O5—C9—O1—C1 and O2—C1—O1—C9 torsion angles are, respectively, 57.23 (13) and 3.46 (14)° while the O9—C17—O8—C25 and O12—C25—O8—C17 torsion angles are, respectively, −55.71 (13) and −5.51 (15)°. The positions of the substituents on the 1,3-dioxane rings are the same as for I and all four rings are in approximate chair forms. Puckering analyses gave Q = 0.5533 (10) Å, θ = 177.07 (10) and φ = 73.5 (19)° for the ring containing O3 with corresponding values of 0.5486 (10) Å, 177.14 (10) and 310 (2)°, respectively, for that containing O6, 0.5494 (10) Å, 5.32 (10) and 259.2 (11)°, respectively for that containing O10 and 0.5502 (10) Å, 4.03 (10) and 128.7 (15)°, respectively for that containing O13. In both molecules, the puckering amplitudes are all comparable with the differences in the angular values resulting from the conventions used to define them (Evans & Boeyens, 1989 ▸).
Figure 2.
The asymmetric unit of II with 50% probability displacement ellipsoids. The C—H⋯O hydrogen bonds are indicated by dashed lines.
Supramolecular features
Unlike many carboxylic acids, compound I does not form hydrogen-bonded dimers in the crystal but rather zigzag chains along the c-axis direction through O2—H2⋯O3 hydrogen bonds (Table 1 ▸ and Fig. 3 ▸). These are connected into ‘tubes’ by C8—H8B⋯O1 hydrogen bonds (Fig. 4 ▸), with these units further linked into a three-dimensional network by C6—H6A⋯O4 hydrogen bonds on all sides of the ‘tube’ (Figs. 3 ▸ and 4 ▸).
Table 1. Hydrogen-bond geometry (Å, °) for I .
| D—H⋯A | D—H | H⋯A | D⋯A | D—H⋯A |
|---|---|---|---|---|
| O2—H2⋯O3i | 0.909 (17) | 1.804 (17) | 2.7086 (9) | 172.6 (14) |
| C6—H6A⋯O4ii | 0.979 (15) | 2.527 (15) | 3.4958 (13) | 170.4 (12) |
| C8—H8B⋯O1iii | 0.984 (14) | 2.405 (14) | 3.3864 (12) | 174.8 (11) |
Symmetry codes: (i) 
; (ii) 
; (iii) 
.
Figure 3.
Packing of I viewed along the b-axis direction with O—H⋯O and C—H⋯O hydrogen bonds depicted, respectively, by red and black dashed lines.
Figure 4.
Packing of I viewed along the c-axis direction with C—H⋯O hydrogen bonds depicted by black dashed lines.
The independent molecules in compound II are connected by C19—H19A⋯O7 and C27—H27A⋯O7 hydrogen bonds (Table 2 ▸ and Fig. 5 ▸) and these units are joined into chains extending along the b-axis direction by C3—H3B⋯O10 and C11—H11B⋯O10 hydrogen bonds. These are linked into layers parallel to the ab plane by C16—H16C⋯O3 hydrogen bonds (Fig. 5 ▸) with two such layers joined by C5—H5A⋯O9 and C14—H14A⋯O12 hydrogen bonds (Fig. 6 ▸).
Table 2. Hydrogen-bond geometry (Å, °) for (II) .
| D—H⋯A | D—H | H⋯A | D⋯A | D—H⋯A |
|---|---|---|---|---|
| C3—H3B⋯O10i | 0.99 | 2.54 | 3.5043 (16) | 164 |
| C5—H5A⋯O9ii | 0.99 | 2.54 | 3.4723 (18) | 156 |
| C11—H11B⋯O10i | 0.99 | 2.57 | 3.5152 (17) | 161 |
| C14—H14A⋯O12iii | 0.98 | 2.56 | 3.531 (2) | 171 |
| C16—H16C⋯O3iv | 0.98 | 2.53 | 3.4973 (16) | 170 |
| C19—H19A⋯O7 | 0.99 | 2.53 | 3.5095 (17) | 168 |
| C27—H27A⋯O7 | 0.99 | 2.52 | 3.5035 (16) | 170 |
Symmetry codes: (i) 
; (ii) 
; (iii) 
; (iv) 
.
Figure 5.
Plan view of one corrugated sheet in II seen along the c-axis direction with C—H⋯O hydrogen bonds shown as dashed lines.
Figure 6.
Elevation view of the double layer in II seen along the b-axis direction C—H⋯O hydrogen bonds shown as dashed lines.
Database survey
A search of the Cambridge Crystallographic Database (Version 5.40, updated to September 2019; Groom et al., 2016 ▸) with fragment A
yielded only the one structure which is closely related to I and II (B
, WARLIN; Garmendia et al., 2017 ▸). The geometry of the substituted dioxane portion here is similar to those in I and II. In the 22 additional structures found, one, C
, (AKEKOR; Simmons et al., 2011 ▸) contained a single 1,3-dioxane ring. The remaining hits were spirocyclic molecules, e.g. D
(MINPEH; Gao et al., 2018 ▸).
Synthesis and crystallization
Preparation of 2,2,5-trimethoxy-1,3-dioxane-5-carboxylic acid (I):
2,2,5-Trimethoxy-1,3-dioxane-5-carboxylic acid was synthesized as previously reported (Ihre et al., 1998 ▸; Gillies & Fréchet, 2002 ▸; Andrén et al., 2017 ▸). 2,2-Bis(hydroxymethyl)propionic acid (bis-MPA, 30.68 g, 0.229 mol) was added to a 500 ml round-bottom flask equipped with a magnetic stir bar and suspended in acetone (200 ml) under stirring. 2,2-Dimethoxypropane (50.0 ml, 42.5 g, 0.408 mol) and p-toluenesulfonic acid monohydrate (1.17 g, 6.13 mmol) were added to the reaction flask and the residue rinsed down with acetone (50 ml). The reaction was allowed to proceed under stirring at room temperature for 8 h. Subsequently a 1:1 triethylamine:ethanol solution (1 ml) was used to quench the reaction for 3 h. The solvent was evaporated to yield a white solid residue that was then dissolved in dichloromethane (DCM, 300 ml), transferred to a 500 ml separatory funnel and washed with deionized H2O (5 × 50 ml). The organic layer was collected in an Erlenmeyer flask equipped with a stir bar and dried over anhydrous sodium sulfate (Na2SO4) under stirring for 30 min. The Na2SO4 was removed via vacuum filtration, the solvent was removed by rotary evaporation, the crude product was dissolved in fresh acetone (60 ml) and recrystallized at 249 K overnight. The solid was collected by vacuum filtration via a fritted glass funnel and dried under high vacuum overnight to yield the protected acid as a colorless crystalline solid (17.815 g, 0.102 mol, 44.7%) 1H NMR (400 MHz, CDCl3): δ 1.20 (s, 3H, –CH3), 1.41 (s, 3H, –CH3), 1.44 (s, 3H, –CH3), 3.68 (d, 2H, –CH2O-, J = 12.0 Hz), 4.19 (d, 2H, –CH2O–, J = 12.0 Hz). 13C NMR (75 MHz, CDCl3): δ 18.48 (CH3), 21.89 (CH3), 25.59 (CH3), 41.82 (C), 66.11 (CH2), 98.55 (C), 179.52 (C).
Synthesis of 2,2,5-trimethoxy-1,3-dioxane-5-carboxylic anhydride (II):
2,2,5-Trimethoxy-1,3-dioxane-5-carboxylic anhydride was prepared according to the literature but with an optimized purification (Malkoch et al., 2002 ▸; Giesen et al., 2018 ▸). Isopropylidene-protected acid (I, 2.334 g, 13.40 mmol) was added to a 100 ml round-bottom flask equipped with a stir bar and the solid was dissolved in dichloromethane (25 ml). N,N-Dicyclohexylcarbodiimide was warmed to a liquid, transferred to a tared vial (1.349 g, 6.58 mmol) and dissolved in dichloromethane (10 ml). This solution was slowly added to the acid while stirring and the reaction was allowed to proceed overnight. The solid dicyclohexylurea (DCU) that formed was removed via gravity filtration through fluted Q2 filter paper. The filtrate was collected and evaporated to dryness in vacuo affording a viscous oil that was subsequently dissolved in a minimal amount of diethyl ether under stirring and the remaining solid again removed via gravity filtration using Q2 filter paper. This filtrate was collected, the solvent removed, and the resulting residue dissolved in a minimal amount of warm hexanes. This solution was stirred overnight, affording a white solid that was removed via filtration and the filtrate was evaporated to yield the anhydride as a transparent viscous oil (1.956 g, 5.92 mmol, 88.4%). This was previously reported (Giesen et al., 2018 ▸) and crystals of the anhydride were grown from hexanes. Additional purification can be achieved with removal of additional DCU by dissolving the crude viscous product in warm hexanes and cooling the solution at 276 K overnight to precipitate out additional DCU. This white solid was removed by vacuum filtration and the hexane evaporated yielding a transparent, viscous oil. This precipitation procedure was repeated as needed until a pure product was obtained, as judged by NMR. 1H NMR (400 MHz, CDCl3): δ 1.21 (s, 6H, –CH3), 1.42 (s, 6H, –CH3), 1.45 (s, 6H, –CH3), 3.68 (d, 4H, –CH2O–, J = 12.0 Hz), 4.18 (d, 4H, –CH2O–, J = 12.0 Hz). 13C NMR (100 MHz, CDCl3): δ 17.80 (CH3), 21.70 (CH3), 25.70 (CH3), 43.79 (C), 65.81 (CH2), 98.53 (C), 169.63 (C). Elemental analysis: calculated for C16H26O7: C, 58.17; H, 7.93; 33.90. Found: C, 57.29; H, 8.30; O, 34.22.
Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3 ▸. H atoms in II were included as riding contributions in idealized positions with C—H = 0.98–0.99 Å and U iso(H) = 1.2U eq(C) or 1.5U eq(C-methyl).
Table 3. Experimental details.
| I | II | |
|---|---|---|
| Crystal data | ||
| Chemical formula | C8H14O4 | C16H26O7 |
| M r | 174.19 | 330.37 |
| Crystal system, space group | Monoclinic, C2/c | Triclinic, P
|
| Temperature (K) | 150 | 100 |
| a, b, c (Å) | 16.9457 (8), 9.6453 (5), 12.1052 (6) | 10.355 (4), 11.928 (5), 14.496 (6) |
| α, β, γ (°) | 90, 116.986 (1), 90 | 73.128 (5), 84.900 (5), 89.499 (6) |
| V (Å3) | 1763.12 (15) | 1706.3 (11) |
| Z | 8 | 4 |
| Radiation type | Mo Kα | Mo Kα |
| μ (mm−1) | 0.11 | 0.10 |
| Crystal size (mm) | 0.35 × 0.32 × 0.25 | 0.30 × 0.30 × 0.22 |
| Data collection | ||
| Diffractometer | Bruker SMART APEX CCD | Bruker SMART APEX CCD |
| Absorption correction | Multi-scan (SADABS; Krause et al., 2015 ▸) | Multi-scan (SADABS; Krause et al., 2015 ▸) |
| T min, T max | 0.91, 0.97 | 0.97, 0.98 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 16506, 2367, 2035 | 30041, 8606, 7451 |
| R int | 0.026 | 0.044 |
| (sin θ/λ)max (Å−1) | 0.685 | 0.687 |
| Refinement | ||
| R[F 2 > 2σ(F 2)], wR(F 2), S | 0.039, 0.113, 1.07 | 0.040, 0.109, 1.04 |
| No. of reflections | 2367 | 8606 |
| No. of parameters | 165 | 427 |
| H-atom treatment | All H-atom parameters refined | H-atom parameters constrained |
| Δρmax, Δρmin (e Å−3) | 0.44, −0.18 | 0.35, −0.32 |
Supplementary Material
Crystal structure: contains datablock(s) global, I, II. DOI: 10.1107/S2056989019016670/hb7867sup1.cif
Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989019016670/hb7867Isup2.hkl
Structure factors: contains datablock(s) II. DOI: 10.1107/S2056989019016670/hb7867IIsup3.hkl
13C and 1H NMR spectra. DOI: 10.1107/S2056989019016670/hb7867sup4.docx
Additional supporting information: crystallographic information; 3D view; checkCIF report
Acknowledgments
JTM thanks Tulane University for support of the Tulane Crystallography Laboratory.
supplementary crystallographic information
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid (I). Crystal data
| C8H14O4 | F(000) = 752 |
| Mr = 174.19 | Dx = 1.312 Mg m−3 |
| Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
| a = 16.9457 (8) Å | Cell parameters from 8540 reflections |
| b = 9.6453 (5) Å | θ = 2.5–29.1° |
| c = 12.1052 (6) Å | µ = 0.11 mm−1 |
| β = 116.986 (1)° | T = 150 K |
| V = 1763.12 (15) Å3 | Block, colourless |
| Z = 8 | 0.35 × 0.32 × 0.25 mm |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid (I). Data collection
| Bruker SMART APEX CCD diffractometer | 2367 independent reflections |
| Radiation source: fine-focus sealed tube | 2035 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.026 |
| Detector resolution: 8.3333 pixels mm-1 | θmax = 29.1°, θmin = 2.5° |
| φ and ω scans | h = −23→23 |
| Absorption correction: multi-scan (SADABS; Krause et al., 2015) | k = −13→13 |
| Tmin = 0.91, Tmax = 0.97 | l = −16→16 |
| 16506 measured reflections |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid (I). Refinement
| Refinement on F2 | Primary atom site location: dual |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.039 | Hydrogen site location: difference Fourier map |
| wR(F2) = 0.113 | All H-atom parameters refined |
| S = 1.07 | w = 1/[σ2(Fo2) + (0.0774P)2 + 0.3458P] where P = (Fo2 + 2Fc2)/3 |
| 2367 reflections | (Δ/σ)max = 0.001 |
| 165 parameters | Δρmax = 0.44 e Å−3 |
| 0 restraints | Δρmin = −0.18 e Å−3 |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid (I). Special details
| Experimental. The diffraction data were obtained from 3 sets of 400 frames, each of width 0.5° in ω, colllected at φ = 0.00, 90.00 and 180.00° and 2 sets of 800 frames, each of width 0.45° in φ, collected at ω = –30.00 and 210.00°. The scan time was 10 sec/frame. |
| Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
| Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid (I). Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| O1 | 0.39277 (7) | 0.35303 (8) | 0.10104 (8) | 0.0395 (2) | |
| O2 | 0.35826 (5) | 0.54688 (7) | 0.16844 (7) | 0.0280 (2) | |
| H2 | 0.3661 (10) | 0.5831 (16) | 0.1048 (16) | 0.044 (4)* | |
| O3 | 0.36941 (4) | 0.33124 (7) | 0.47442 (6) | 0.01898 (17) | |
| O4 | 0.37935 (4) | 0.12345 (7) | 0.38268 (6) | 0.01931 (17) | |
| C1 | 0.36963 (6) | 0.41082 (10) | 0.16968 (8) | 0.01841 (19) | |
| C2 | 0.34712 (6) | 0.33493 (9) | 0.26155 (7) | 0.01538 (18) | |
| C3 | 0.38203 (6) | 0.41384 (9) | 0.38447 (8) | 0.01846 (19) | |
| H3 | 0.4442 (8) | 0.4359 (13) | 0.4139 (12) | 0.025 (3)* | |
| H3B | 0.3511 (9) | 0.5007 (14) | 0.3792 (12) | 0.028 (3)* | |
| C4 | 0.41050 (6) | 0.19614 (9) | 0.49632 (8) | 0.0176 (2) | |
| C5 | 0.39283 (6) | 0.19347 (9) | 0.28855 (8) | 0.0194 (2) | |
| H5 | 0.4560 (9) | 0.2045 (15) | 0.3127 (13) | 0.034 (3)* | |
| H5B | 0.3649 (9) | 0.1329 (14) | 0.2151 (13) | 0.031 (3)* | |
| C6 | 0.24588 (6) | 0.31871 (11) | 0.20277 (9) | 0.0251 (2) | |
| H6A | 0.2160 (9) | 0.4086 (15) | 0.1885 (13) | 0.031 (3)* | |
| H6B | 0.2316 (8) | 0.2611 (14) | 0.2616 (12) | 0.028 (3)* | |
| H6C | 0.2246 (10) | 0.2711 (16) | 0.1240 (14) | 0.042 (4)* | |
| C7 | 0.37499 (7) | 0.11697 (11) | 0.57215 (9) | 0.0252 (2) | |
| H7A | 0.3976 (10) | 0.1590 (16) | 0.6557 (15) | 0.045 (4)* | |
| H7B | 0.3967 (10) | 0.0208 (16) | 0.5805 (14) | 0.037 (4)* | |
| H7C | 0.3113 (10) | 0.1106 (16) | 0.5286 (14) | 0.039 (4)* | |
| C8 | 0.51093 (6) | 0.20861 (11) | 0.56270 (9) | 0.0256 (2) | |
| H8A | 0.5272 (10) | 0.2602 (16) | 0.6373 (14) | 0.039 (4)* | |
| H8B | 0.5353 (9) | 0.2497 (15) | 0.5103 (13) | 0.034 (3)* | |
| H8C | 0.5394 (9) | 0.1170 (16) | 0.5863 (13) | 0.034 (3)* |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid (I). Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0713 (6) | 0.0306 (4) | 0.0381 (5) | 0.0155 (4) | 0.0436 (5) | 0.0086 (3) |
| O2 | 0.0493 (5) | 0.0185 (3) | 0.0265 (4) | 0.0005 (3) | 0.0263 (3) | 0.0028 (3) |
| O3 | 0.0299 (3) | 0.0157 (3) | 0.0163 (3) | 0.0032 (2) | 0.0147 (3) | 0.0010 (2) |
| O4 | 0.0287 (3) | 0.0139 (3) | 0.0173 (3) | −0.0008 (2) | 0.0122 (3) | −0.0004 (2) |
| C1 | 0.0209 (4) | 0.0207 (4) | 0.0148 (4) | 0.0014 (3) | 0.0091 (3) | 0.0013 (3) |
| C2 | 0.0189 (4) | 0.0159 (4) | 0.0134 (4) | 0.0005 (3) | 0.0091 (3) | 0.0000 (3) |
| C3 | 0.0285 (4) | 0.0144 (4) | 0.0152 (4) | −0.0004 (3) | 0.0123 (3) | −0.0001 (3) |
| C4 | 0.0229 (4) | 0.0149 (4) | 0.0158 (4) | 0.0005 (3) | 0.0094 (3) | 0.0013 (3) |
| C5 | 0.0284 (4) | 0.0163 (4) | 0.0172 (4) | 0.0037 (3) | 0.0136 (3) | 0.0003 (3) |
| C6 | 0.0195 (4) | 0.0307 (5) | 0.0232 (5) | −0.0006 (4) | 0.0081 (4) | 0.0039 (4) |
| C7 | 0.0348 (5) | 0.0233 (5) | 0.0227 (5) | −0.0022 (4) | 0.0175 (4) | 0.0037 (4) |
| C8 | 0.0219 (4) | 0.0301 (5) | 0.0207 (5) | −0.0002 (4) | 0.0062 (4) | 0.0055 (4) |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid (I). Geometric parameters (Å, º)
| O1—C1 | 1.2043 (11) | C4—C7 | 1.5129 (12) |
| O2—C1 | 1.3255 (12) | C4—C8 | 1.5216 (12) |
| O2—H2 | 0.909 (17) | C5—H5 | 0.979 (14) |
| O3—C3 | 1.4414 (10) | C5—H5B | 0.986 (14) |
| O3—C4 | 1.4442 (11) | C6—H6A | 0.979 (14) |
| O4—C4 | 1.4155 (10) | C6—H6B | 1.015 (13) |
| O4—C5 | 1.4294 (10) | C6—H6C | 0.968 (15) |
| C1—C2 | 1.5176 (11) | C7—H7A | 0.991 (16) |
| C2—C5 | 1.5293 (12) | C7—H7B | 0.986 (15) |
| C2—C3 | 1.5312 (12) | C7—H7C | 0.964 (15) |
| C2—C6 | 1.5382 (12) | C8—H8A | 0.955 (15) |
| C3—H3 | 0.970 (13) | C8—H8B | 0.984 (14) |
| C3—H3B | 0.975 (13) | C8—H8C | 0.985 (15) |
| C1—O2—H2 | 108.3 (10) | O4—C5—C2 | 110.07 (7) |
| C3—O3—C4 | 114.39 (6) | O4—C5—H5 | 111.2 (8) |
| C4—O4—C5 | 114.63 (7) | C2—C5—H5 | 110.2 (9) |
| O1—C1—O2 | 122.79 (8) | O4—C5—H5B | 104.7 (8) |
| O1—C1—C2 | 123.44 (9) | C2—C5—H5B | 110.3 (8) |
| O2—C1—C2 | 113.72 (7) | H5—C5—H5B | 110.2 (11) |
| C1—C2—C5 | 108.39 (7) | C2—C6—H6A | 111.8 (8) |
| C1—C2—C3 | 110.95 (7) | C2—C6—H6B | 107.6 (7) |
| C5—C2—C3 | 107.51 (7) | H6A—C6—H6B | 109.9 (11) |
| C1—C2—C6 | 107.98 (7) | C2—C6—H6C | 110.0 (9) |
| C5—C2—C6 | 111.02 (8) | H6A—C6—H6C | 108.3 (13) |
| C3—C2—C6 | 110.98 (7) | H6B—C6—H6C | 109.3 (12) |
| O3—C3—C2 | 109.57 (7) | C4—C7—H7A | 109.6 (9) |
| O3—C3—H3 | 110.6 (8) | C4—C7—H7B | 107.7 (8) |
| C2—C3—H3 | 110.0 (7) | H7A—C7—H7B | 109.1 (13) |
| O3—C3—H3B | 105.3 (8) | C4—C7—H7C | 110.8 (9) |
| C2—C3—H3B | 113.8 (8) | H7A—C7—H7C | 113.7 (13) |
| H3—C3—H3B | 107.3 (11) | H7B—C7—H7C | 105.7 (13) |
| O4—C4—O3 | 109.42 (7) | C4—C8—H8A | 108.3 (9) |
| O4—C4—C7 | 105.31 (7) | C4—C8—H8B | 112.8 (8) |
| O3—C4—C7 | 105.98 (7) | H8A—C8—H8B | 112.0 (13) |
| O4—C4—C8 | 112.76 (7) | C4—C8—H8C | 111.4 (8) |
| O3—C4—C8 | 110.86 (7) | H8A—C8—H8C | 107.4 (13) |
| C7—C4—C8 | 112.14 (8) | H8B—C8—H8C | 104.8 (12) |
| O1—C1—C2—C5 | 22.55 (12) | C5—O4—C4—O3 | 56.51 (9) |
| O2—C1—C2—C5 | −159.88 (8) | C5—O4—C4—C7 | 170.04 (7) |
| O1—C1—C2—C3 | 140.38 (10) | C5—O4—C4—C8 | −67.36 (10) |
| O2—C1—C2—C3 | −42.05 (10) | C3—O3—C4—O4 | −56.03 (9) |
| O1—C1—C2—C6 | −97.79 (11) | C3—O3—C4—C7 | −169.12 (7) |
| O2—C1—C2—C6 | 79.77 (10) | C3—O3—C4—C8 | 68.95 (9) |
| C4—O3—C3—C2 | 57.03 (9) | C4—O4—C5—C2 | −58.36 (10) |
| C1—C2—C3—O3 | −172.93 (7) | C1—C2—C5—O4 | 175.13 (7) |
| C5—C2—C3—O3 | −54.57 (9) | C3—C2—C5—O4 | 55.13 (9) |
| C6—C2—C3—O3 | 67.02 (9) | C6—C2—C5—O4 | −66.43 (9) |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid (I). Hydrogen-bond geometry (Å, º)
| D—H···A | D—H | H···A | D···A | D—H···A |
| O2—H2···O3i | 0.909 (17) | 1.804 (17) | 2.7086 (9) | 172.6 (14) |
| C6—H6A···O4ii | 0.979 (15) | 2.527 (15) | 3.4958 (13) | 170.4 (12) |
| C8—H8B···O1iii | 0.984 (14) | 2.405 (14) | 3.3864 (12) | 174.8 (11) |
Symmetry codes: (i) x, −y+1, z−1/2; (ii) −x+1/2, y+1/2, −z+1/2; (iii) −x+1, y, −z+1/2.
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic anhydride (II). Crystal data
| C16H26O7 | Z = 4 |
| Mr = 330.37 | F(000) = 712 |
| Triclinic, P1 | Dx = 1.286 Mg m−3 |
| a = 10.355 (4) Å | Mo Kα radiation, λ = 0.71073 Å |
| b = 11.928 (5) Å | Cell parameters from 9690 reflections |
| c = 14.496 (6) Å | θ = 2.4–29.6° |
| α = 73.128 (5)° | µ = 0.10 mm−1 |
| β = 84.900 (5)° | T = 100 K |
| γ = 89.499 (6)° | Block, colourless |
| V = 1706.3 (11) Å3 | 0.30 × 0.30 × 0.22 mm |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic anhydride (II). Data collection
| Bruker SMART APEX CCD diffractometer | 8606 independent reflections |
| Radiation source: fine-focus sealed tube | 7451 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.044 |
| Detector resolution: 8.3333 pixels mm-1 | θmax = 29.3°, θmin = 2.0° |
| φ and ω scans | h = −13→14 |
| Absorption correction: multi-scan (SADABS; Krause et al., 2015) | k = −16→15 |
| Tmin = 0.97, Tmax = 0.98 | l = −19→19 |
| 30041 measured reflections |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic anhydride (II). Refinement
| Refinement on F2 | Primary atom site location: dual |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.109 | H-atom parameters constrained |
| S = 1.04 | w = 1/[σ2(Fo2) + (0.0556P)2 + 0.3868P] where P = (Fo2 + 2Fc2)/3 |
| 8606 reflections | (Δ/σ)max = 0.001 |
| 427 parameters | Δρmax = 0.35 e Å−3 |
| 0 restraints | Δρmin = −0.32 e Å−3 |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic anhydride (II). Special details
| Experimental. The diffraction data were obtained from 3 sets of 400 frames, each of width 0.5° in ω, colllected at φ = 0.00, 90.00 and 180.00° and 2 sets of 800 frames, each of width 0.45° in φ, collected at ω = –30.00 and 210.00°. The scan time was 20 sec/frame. |
| Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
| Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. H-atoms attached to carbon were placed in calculated positions (C—H = 0.95 - 0.98 Å). All were included as riding contributions with isotropic displacement parameters 1.2 - 1.5 times those of the attached atoms. |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic anhydride (II). Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| O1 | 0.61114 (7) | 0.17397 (6) | 0.38614 (5) | 0.01811 (15) | |
| O2 | 0.50096 (8) | 0.34387 (7) | 0.35198 (6) | 0.02453 (17) | |
| O3 | 0.20648 (6) | 0.19286 (6) | 0.24679 (5) | 0.01536 (14) | |
| O4 | 0.37528 (7) | 0.08851 (6) | 0.19282 (5) | 0.01796 (15) | |
| O5 | 0.69640 (8) | 0.26493 (7) | 0.48443 (6) | 0.02468 (17) | |
| O6 | 0.77584 (7) | 0.26736 (6) | 0.20400 (5) | 0.01762 (15) | |
| O7 | 0.85266 (7) | 0.41175 (6) | 0.26717 (5) | 0.01698 (15) | |
| C1 | 0.50623 (9) | 0.24255 (9) | 0.35590 (7) | 0.01594 (19) | |
| C2 | 0.40734 (9) | 0.17221 (8) | 0.32402 (7) | 0.01479 (19) | |
| C3 | 0.47061 (9) | 0.13905 (9) | 0.23488 (7) | 0.01764 (19) | |
| H3A | 0.509546 | 0.209880 | 0.186491 | 0.021* | |
| H3B | 0.540504 | 0.082334 | 0.254818 | 0.021* | |
| C4 | 0.26705 (9) | 0.16139 (9) | 0.16544 (7) | 0.01538 (19) | |
| C5 | 0.29198 (9) | 0.25081 (9) | 0.29146 (7) | 0.01568 (19) | |
| H5A | 0.244737 | 0.268096 | 0.348059 | 0.019* | |
| H5B | 0.323569 | 0.325907 | 0.244884 | 0.019* | |
| C6 | 0.36290 (10) | 0.06178 (9) | 0.40559 (8) | 0.0201 (2) | |
| H6A | 0.437550 | 0.011721 | 0.423812 | 0.030* | |
| H6B | 0.298009 | 0.018822 | 0.383227 | 0.030* | |
| H6C | 0.324777 | 0.084269 | 0.461837 | 0.030* | |
| C7 | 0.16859 (10) | 0.08444 (9) | 0.14008 (8) | 0.0197 (2) | |
| H7A | 0.137648 | 0.022159 | 0.198378 | 0.030* | |
| H7B | 0.209200 | 0.049489 | 0.091533 | 0.030* | |
| H7C | 0.095236 | 0.131909 | 0.113908 | 0.030* | |
| C8 | 0.30637 (11) | 0.26922 (9) | 0.08043 (7) | 0.0213 (2) | |
| H8A | 0.231143 | 0.319476 | 0.065223 | 0.032* | |
| H8B | 0.337824 | 0.244353 | 0.023790 | 0.032* | |
| H8C | 0.375355 | 0.312944 | 0.097812 | 0.032* | |
| C9 | 0.71419 (10) | 0.22328 (9) | 0.41881 (7) | 0.01674 (19) | |
| C10 | 0.84583 (9) | 0.20922 (8) | 0.36723 (7) | 0.01496 (18) | |
| C11 | 0.83536 (10) | 0.17628 (8) | 0.27399 (7) | 0.01655 (19) | |
| H11A | 0.923038 | 0.161976 | 0.246924 | 0.020* | |
| H11B | 0.783369 | 0.102966 | 0.288491 | 0.020* | |
| C12 | 0.84132 (10) | 0.37818 (9) | 0.18094 (7) | 0.01700 (19) | |
| C13 | 0.91677 (10) | 0.32801 (8) | 0.33964 (7) | 0.01650 (19) | |
| H13A | 0.918581 | 0.355697 | 0.397628 | 0.020* | |
| H13B | 1.007414 | 0.319629 | 0.314757 | 0.020* | |
| C14 | 0.92243 (10) | 0.11550 (9) | 0.43651 (8) | 0.0221 (2) | |
| H14A | 0.925743 | 0.135002 | 0.497449 | 0.033* | |
| H14B | 1.010801 | 0.112858 | 0.406871 | 0.033* | |
| H14C | 0.879586 | 0.038874 | 0.449389 | 0.033* | |
| C15 | 0.75121 (12) | 0.46587 (10) | 0.12292 (9) | 0.0268 (2) | |
| H15A | 0.667202 | 0.462130 | 0.160693 | 0.040* | |
| H15B | 0.739079 | 0.447442 | 0.062590 | 0.040* | |
| H15C | 0.788927 | 0.544884 | 0.107845 | 0.040* | |
| C16 | 0.97334 (11) | 0.37799 (9) | 0.12476 (8) | 0.0216 (2) | |
| H16A | 1.013381 | 0.456339 | 0.107417 | 0.032* | |
| H16B | 0.961933 | 0.356256 | 0.065737 | 0.032* | |
| H16C | 1.029383 | 0.321247 | 0.165093 | 0.032* | |
| O8 | 0.91353 (7) | 0.66447 (6) | 0.36711 (5) | 0.01908 (16) | |
| O9 | 0.80649 (8) | 0.74653 (7) | 0.47388 (6) | 0.02506 (17) | |
| O10 | 0.69272 (7) | 0.91031 (6) | 0.27307 (5) | 0.01648 (15) | |
| O11 | 0.78656 (7) | 0.78188 (6) | 0.19087 (5) | 0.01714 (15) | |
| O12 | 1.03035 (8) | 0.83256 (7) | 0.34106 (6) | 0.02418 (17) | |
| O13 | 1.20111 (7) | 0.58226 (6) | 0.17388 (5) | 0.01848 (15) | |
| O14 | 1.35295 (7) | 0.69110 (6) | 0.22514 (5) | 0.01777 (15) | |
| C17 | 0.80283 (10) | 0.71100 (9) | 0.40517 (7) | 0.01728 (19) | |
| C18 | 0.68200 (9) | 0.70215 (8) | 0.35467 (7) | 0.01530 (19) | |
| C19 | 0.71338 (10) | 0.68437 (8) | 0.25503 (7) | 0.01675 (19) | |
| H19A | 0.763701 | 0.611930 | 0.261691 | 0.020* | |
| H19B | 0.631671 | 0.674776 | 0.227257 | 0.020* | |
| C20 | 0.72594 (10) | 0.89232 (9) | 0.18016 (7) | 0.01614 (19) | |
| C21 | 0.61304 (10) | 0.81907 (9) | 0.33904 (7) | 0.01696 (19) | |
| H21A | 0.529030 | 0.814447 | 0.312520 | 0.020* | |
| H21B | 0.595578 | 0.836590 | 0.401641 | 0.020* | |
| C22 | 0.59509 (11) | 0.60097 (9) | 0.41984 (8) | 0.0232 (2) | |
| H22A | 0.514044 | 0.598390 | 0.390309 | 0.035* | |
| H22B | 0.575684 | 0.613336 | 0.483547 | 0.035* | |
| H22C | 0.640143 | 0.526714 | 0.427203 | 0.035* | |
| C23 | 0.83068 (11) | 0.98287 (10) | 0.13041 (8) | 0.0226 (2) | |
| H23A | 0.903529 | 0.973284 | 0.170656 | 0.034* | |
| H23B | 0.795553 | 1.061567 | 0.120902 | 0.034* | |
| H23C | 0.860766 | 0.972364 | 0.067464 | 0.034* | |
| C24 | 0.60689 (10) | 0.90425 (9) | 0.12294 (8) | 0.0196 (2) | |
| H24A | 0.633618 | 0.901436 | 0.057087 | 0.029* | |
| H24B | 0.565364 | 0.979148 | 0.120183 | 0.029* | |
| H24C | 0.545396 | 0.839795 | 0.154879 | 0.029* | |
| C25 | 1.02532 (10) | 0.73291 (9) | 0.34016 (7) | 0.01695 (19) | |
| C26 | 1.13437 (9) | 0.66492 (8) | 0.30582 (7) | 0.01591 (19) | |
| C27 | 1.09366 (9) | 0.63078 (9) | 0.21756 (7) | 0.0179 (2) | |
| H27A | 1.021396 | 0.572587 | 0.238381 | 0.022* | |
| H27B | 1.062981 | 0.700902 | 0.169665 | 0.022* | |
| C28 | 1.31372 (10) | 0.65704 (9) | 0.14491 (7) | 0.0171 (2) | |
| C29 | 1.25393 (10) | 0.74666 (9) | 0.27107 (8) | 0.0182 (2) | |
| H29A | 1.229428 | 0.820862 | 0.224740 | 0.022* | |
| H29B | 1.287269 | 0.765368 | 0.326907 | 0.022* | |
| C30 | 1.16462 (10) | 0.55598 (9) | 0.38751 (8) | 0.0207 (2) | |
| H30A | 1.190672 | 0.580001 | 0.442426 | 0.031* | |
| H30B | 1.235311 | 0.513214 | 0.364143 | 0.031* | |
| H30C | 1.087204 | 0.505140 | 0.408148 | 0.031* | |
| C31 | 1.29214 (11) | 0.76289 (10) | 0.05887 (8) | 0.0236 (2) | |
| H31A | 1.221283 | 0.809470 | 0.077099 | 0.035* | |
| H31B | 1.269615 | 0.736065 | 0.004421 | 0.035* | |
| H31C | 1.371653 | 0.811087 | 0.039866 | 0.035* | |
| C32 | 1.42178 (10) | 0.58090 (9) | 0.12077 (8) | 0.0211 (2) | |
| H32A | 1.501898 | 0.627907 | 0.099325 | 0.032* | |
| H32B | 1.398129 | 0.549594 | 0.068966 | 0.032* | |
| H32C | 1.435184 | 0.515969 | 0.178409 | 0.032* |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic anhydride (II). Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0127 (3) | 0.0173 (3) | 0.0257 (4) | 0.0006 (3) | −0.0049 (3) | −0.0074 (3) |
| O2 | 0.0246 (4) | 0.0174 (4) | 0.0347 (4) | 0.0021 (3) | −0.0099 (3) | −0.0105 (3) |
| O3 | 0.0121 (3) | 0.0186 (3) | 0.0166 (3) | 0.0000 (3) | −0.0012 (2) | −0.0071 (3) |
| O4 | 0.0146 (3) | 0.0178 (3) | 0.0248 (4) | 0.0030 (3) | −0.0044 (3) | −0.0107 (3) |
| O5 | 0.0211 (4) | 0.0332 (4) | 0.0234 (4) | 0.0008 (3) | −0.0028 (3) | −0.0138 (3) |
| O6 | 0.0183 (3) | 0.0160 (3) | 0.0203 (3) | 0.0012 (3) | −0.0070 (3) | −0.0066 (3) |
| O7 | 0.0213 (4) | 0.0127 (3) | 0.0178 (3) | 0.0020 (3) | −0.0047 (3) | −0.0049 (3) |
| C1 | 0.0139 (4) | 0.0172 (5) | 0.0162 (4) | 0.0006 (4) | −0.0013 (3) | −0.0041 (4) |
| C2 | 0.0124 (4) | 0.0144 (4) | 0.0178 (4) | 0.0000 (3) | −0.0021 (3) | −0.0049 (3) |
| C3 | 0.0124 (4) | 0.0200 (5) | 0.0231 (5) | 0.0012 (4) | −0.0020 (4) | −0.0103 (4) |
| C4 | 0.0140 (4) | 0.0162 (4) | 0.0166 (4) | 0.0011 (3) | −0.0008 (3) | −0.0060 (4) |
| C5 | 0.0141 (4) | 0.0160 (4) | 0.0186 (4) | 0.0017 (3) | −0.0034 (3) | −0.0073 (4) |
| C6 | 0.0196 (5) | 0.0176 (5) | 0.0207 (5) | −0.0032 (4) | −0.0043 (4) | −0.0011 (4) |
| C7 | 0.0183 (5) | 0.0199 (5) | 0.0226 (5) | −0.0022 (4) | −0.0039 (4) | −0.0082 (4) |
| C8 | 0.0240 (5) | 0.0211 (5) | 0.0172 (5) | −0.0030 (4) | 0.0005 (4) | −0.0034 (4) |
| C9 | 0.0146 (4) | 0.0161 (4) | 0.0189 (5) | −0.0009 (4) | −0.0035 (3) | −0.0036 (4) |
| C10 | 0.0127 (4) | 0.0143 (4) | 0.0177 (4) | 0.0005 (3) | −0.0037 (3) | −0.0037 (3) |
| C11 | 0.0168 (4) | 0.0131 (4) | 0.0204 (5) | 0.0015 (3) | −0.0031 (4) | −0.0057 (4) |
| C12 | 0.0200 (5) | 0.0147 (4) | 0.0168 (4) | 0.0030 (4) | −0.0042 (4) | −0.0047 (4) |
| C13 | 0.0158 (4) | 0.0154 (4) | 0.0179 (4) | −0.0013 (4) | −0.0054 (4) | −0.0032 (4) |
| C14 | 0.0179 (5) | 0.0202 (5) | 0.0244 (5) | 0.0031 (4) | −0.0052 (4) | 0.0005 (4) |
| C15 | 0.0323 (6) | 0.0230 (5) | 0.0254 (5) | 0.0106 (5) | −0.0115 (5) | −0.0051 (4) |
| C16 | 0.0236 (5) | 0.0200 (5) | 0.0195 (5) | 0.0001 (4) | 0.0007 (4) | −0.0038 (4) |
| O8 | 0.0130 (3) | 0.0183 (3) | 0.0265 (4) | −0.0002 (3) | −0.0001 (3) | −0.0078 (3) |
| O9 | 0.0234 (4) | 0.0331 (4) | 0.0206 (4) | 0.0007 (3) | −0.0015 (3) | −0.0110 (3) |
| O10 | 0.0210 (4) | 0.0126 (3) | 0.0167 (3) | −0.0014 (3) | −0.0006 (3) | −0.0059 (3) |
| O11 | 0.0163 (3) | 0.0159 (3) | 0.0197 (3) | −0.0001 (3) | 0.0016 (3) | −0.0068 (3) |
| O12 | 0.0233 (4) | 0.0181 (4) | 0.0319 (4) | −0.0012 (3) | 0.0012 (3) | −0.0095 (3) |
| O13 | 0.0138 (3) | 0.0179 (3) | 0.0250 (4) | −0.0027 (3) | 0.0002 (3) | −0.0088 (3) |
| O14 | 0.0134 (3) | 0.0195 (4) | 0.0215 (4) | −0.0015 (3) | −0.0020 (3) | −0.0074 (3) |
| C17 | 0.0154 (4) | 0.0160 (4) | 0.0189 (5) | 0.0000 (4) | 0.0011 (4) | −0.0034 (4) |
| C18 | 0.0132 (4) | 0.0132 (4) | 0.0192 (4) | −0.0007 (3) | 0.0007 (3) | −0.0048 (3) |
| C19 | 0.0168 (5) | 0.0128 (4) | 0.0222 (5) | −0.0005 (4) | −0.0016 (4) | −0.0075 (4) |
| C20 | 0.0181 (5) | 0.0148 (4) | 0.0163 (4) | −0.0009 (4) | −0.0008 (3) | −0.0059 (3) |
| C21 | 0.0164 (5) | 0.0157 (4) | 0.0184 (5) | 0.0009 (4) | 0.0011 (4) | −0.0051 (4) |
| C22 | 0.0207 (5) | 0.0180 (5) | 0.0267 (5) | −0.0051 (4) | 0.0016 (4) | −0.0008 (4) |
| C23 | 0.0249 (5) | 0.0215 (5) | 0.0196 (5) | −0.0082 (4) | −0.0009 (4) | −0.0031 (4) |
| C24 | 0.0204 (5) | 0.0201 (5) | 0.0198 (5) | 0.0002 (4) | −0.0045 (4) | −0.0074 (4) |
| C25 | 0.0152 (4) | 0.0184 (5) | 0.0168 (4) | −0.0007 (4) | −0.0028 (3) | −0.0039 (4) |
| C26 | 0.0136 (4) | 0.0150 (4) | 0.0190 (5) | −0.0010 (3) | −0.0023 (3) | −0.0045 (4) |
| C27 | 0.0129 (4) | 0.0200 (5) | 0.0226 (5) | −0.0009 (4) | −0.0022 (4) | −0.0086 (4) |
| C28 | 0.0158 (5) | 0.0159 (5) | 0.0192 (5) | −0.0023 (4) | −0.0022 (4) | −0.0044 (4) |
| C29 | 0.0155 (5) | 0.0172 (5) | 0.0228 (5) | −0.0024 (4) | −0.0007 (4) | −0.0074 (4) |
| C30 | 0.0188 (5) | 0.0180 (5) | 0.0229 (5) | 0.0009 (4) | −0.0033 (4) | −0.0019 (4) |
| C31 | 0.0253 (5) | 0.0213 (5) | 0.0216 (5) | 0.0008 (4) | −0.0028 (4) | −0.0020 (4) |
| C32 | 0.0171 (5) | 0.0205 (5) | 0.0254 (5) | 0.0003 (4) | 0.0005 (4) | −0.0068 (4) |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic anhydride (II). Geometric parameters (Å, º)
| O1—C1 | 1.3792 (12) | O8—C25 | 1.3820 (13) |
| O1—C9 | 1.4041 (12) | O8—C17 | 1.4073 (13) |
| O2—C1 | 1.1943 (13) | O9—C17 | 1.1939 (13) |
| O3—C4 | 1.4304 (12) | O10—C21 | 1.4321 (12) |
| O3—C5 | 1.4330 (12) | O10—C20 | 1.4360 (12) |
| O4—C4 | 1.4251 (12) | O11—C20 | 1.4274 (13) |
| O4—C3 | 1.4284 (12) | O11—C19 | 1.4333 (12) |
| O5—C9 | 1.1946 (13) | O12—C25 | 1.1942 (14) |
| O6—C12 | 1.4276 (13) | O13—C28 | 1.4301 (12) |
| O6—C11 | 1.4314 (12) | O13—C27 | 1.4318 (13) |
| O7—C13 | 1.4301 (12) | O14—C28 | 1.4296 (13) |
| O7—C12 | 1.4331 (13) | O14—C29 | 1.4341 (13) |
| C1—C2 | 1.5135 (14) | C17—C18 | 1.5239 (15) |
| C2—C5 | 1.5336 (14) | C18—C19 | 1.5264 (15) |
| C2—C6 | 1.5346 (14) | C18—C21 | 1.5278 (14) |
| C2—C3 | 1.5482 (14) | C18—C22 | 1.5378 (14) |
| C3—H3A | 0.9900 | C19—H19A | 0.9900 |
| C3—H3B | 0.9900 | C19—H19B | 0.9900 |
| C4—C7 | 1.5152 (14) | C20—C23 | 1.5140 (14) |
| C4—C8 | 1.5293 (14) | C20—C24 | 1.5290 (15) |
| C5—H5A | 0.9900 | C21—H21A | 0.9900 |
| C5—H5B | 0.9900 | C21—H21B | 0.9900 |
| C6—H6A | 0.9800 | C22—H22A | 0.9800 |
| C6—H6B | 0.9800 | C22—H22B | 0.9800 |
| C6—H6C | 0.9800 | C22—H22C | 0.9800 |
| C7—H7A | 0.9800 | C23—H23A | 0.9800 |
| C7—H7B | 0.9800 | C23—H23B | 0.9800 |
| C7—H7C | 0.9800 | C23—H23C | 0.9800 |
| C8—H8A | 0.9800 | C24—H24A | 0.9800 |
| C8—H8B | 0.9800 | C24—H24B | 0.9800 |
| C8—H8C | 0.9800 | C24—H24C | 0.9800 |
| C9—C10 | 1.5273 (15) | C25—C26 | 1.5163 (14) |
| C10—C11 | 1.5259 (14) | C26—C30 | 1.5346 (14) |
| C10—C13 | 1.5312 (14) | C26—C29 | 1.5369 (14) |
| C10—C14 | 1.5368 (14) | C26—C27 | 1.5432 (15) |
| C11—H11A | 0.9900 | C27—H27A | 0.9900 |
| C11—H11B | 0.9900 | C27—H27B | 0.9900 |
| C12—C15 | 1.5112 (14) | C28—C32 | 1.5154 (15) |
| C12—C16 | 1.5281 (15) | C28—C31 | 1.5264 (15) |
| C13—H13A | 0.9900 | C29—H29A | 0.9900 |
| C13—H13B | 0.9900 | C29—H29B | 0.9900 |
| C14—H14A | 0.9800 | C30—H30A | 0.9800 |
| C14—H14B | 0.9800 | C30—H30B | 0.9800 |
| C14—H14C | 0.9800 | C30—H30C | 0.9800 |
| C15—H15A | 0.9800 | C31—H31A | 0.9800 |
| C15—H15B | 0.9800 | C31—H31B | 0.9800 |
| C15—H15C | 0.9800 | C31—H31C | 0.9800 |
| C16—H16A | 0.9800 | C32—H32A | 0.9800 |
| C16—H16B | 0.9800 | C32—H32B | 0.9800 |
| C16—H16C | 0.9800 | C32—H32C | 0.9800 |
| C1—O1—C9 | 118.80 (8) | C25—O8—C17 | 118.48 (8) |
| C4—O3—C5 | 113.91 (7) | C21—O10—C20 | 114.29 (7) |
| C4—O4—C3 | 114.18 (8) | C20—O11—C19 | 114.15 (8) |
| C12—O6—C11 | 113.64 (8) | C28—O13—C27 | 114.50 (8) |
| C13—O7—C12 | 114.10 (8) | C28—O14—C29 | 114.37 (8) |
| O2—C1—O1 | 123.18 (9) | O9—C17—O8 | 121.02 (9) |
| O2—C1—C2 | 126.81 (9) | O9—C17—C18 | 125.63 (9) |
| O1—C1—C2 | 109.90 (8) | O8—C17—C18 | 113.21 (9) |
| C1—C2—C5 | 108.49 (8) | C17—C18—C19 | 112.87 (8) |
| C1—C2—C6 | 111.34 (8) | C17—C18—C21 | 106.98 (8) |
| C5—C2—C6 | 110.85 (8) | C19—C18—C21 | 106.97 (8) |
| C1—C2—C3 | 107.78 (8) | C17—C18—C22 | 108.84 (9) |
| C5—C2—C3 | 107.70 (8) | C19—C18—C22 | 110.24 (8) |
| C6—C2—C3 | 110.56 (9) | C21—C18—C22 | 110.90 (9) |
| O4—C3—C2 | 109.92 (8) | O11—C19—C18 | 111.17 (8) |
| O4—C3—H3A | 109.7 | O11—C19—H19A | 109.4 |
| C2—C3—H3A | 109.7 | C18—C19—H19A | 109.4 |
| O4—C3—H3B | 109.7 | O11—C19—H19B | 109.4 |
| C2—C3—H3B | 109.7 | C18—C19—H19B | 109.4 |
| H3A—C3—H3B | 108.2 | H19A—C19—H19B | 108.0 |
| O4—C4—O3 | 110.43 (8) | O11—C20—O10 | 110.54 (8) |
| O4—C4—C7 | 105.51 (8) | O11—C20—C23 | 105.06 (9) |
| O3—C4—C7 | 105.46 (8) | O10—C20—C23 | 105.60 (8) |
| O4—C4—C8 | 111.28 (8) | O11—C20—C24 | 111.92 (8) |
| O3—C4—C8 | 111.84 (8) | O10—C20—C24 | 110.91 (8) |
| C7—C4—C8 | 112.00 (9) | C23—C20—C24 | 112.51 (9) |
| O3—C5—C2 | 109.66 (8) | O10—C21—C18 | 109.60 (8) |
| O3—C5—H5A | 109.7 | O10—C21—H21A | 109.7 |
| C2—C5—H5A | 109.7 | C18—C21—H21A | 109.7 |
| O3—C5—H5B | 109.7 | O10—C21—H21B | 109.7 |
| C2—C5—H5B | 109.7 | C18—C21—H21B | 109.7 |
| H5A—C5—H5B | 108.2 | H21A—C21—H21B | 108.2 |
| C2—C6—H6A | 109.5 | C18—C22—H22A | 109.5 |
| C2—C6—H6B | 109.5 | C18—C22—H22B | 109.5 |
| H6A—C6—H6B | 109.5 | H22A—C22—H22B | 109.5 |
| C2—C6—H6C | 109.5 | C18—C22—H22C | 109.5 |
| H6A—C6—H6C | 109.5 | H22A—C22—H22C | 109.5 |
| H6B—C6—H6C | 109.5 | H22B—C22—H22C | 109.5 |
| C4—C7—H7A | 109.5 | C20—C23—H23A | 109.5 |
| C4—C7—H7B | 109.5 | C20—C23—H23B | 109.5 |
| H7A—C7—H7B | 109.5 | H23A—C23—H23B | 109.5 |
| C4—C7—H7C | 109.5 | C20—C23—H23C | 109.5 |
| H7A—C7—H7C | 109.5 | H23A—C23—H23C | 109.5 |
| H7B—C7—H7C | 109.5 | H23B—C23—H23C | 109.5 |
| C4—C8—H8A | 109.5 | C20—C24—H24A | 109.5 |
| C4—C8—H8B | 109.5 | C20—C24—H24B | 109.5 |
| H8A—C8—H8B | 109.5 | H24A—C24—H24B | 109.5 |
| C4—C8—H8C | 109.5 | C20—C24—H24C | 109.5 |
| H8A—C8—H8C | 109.5 | H24A—C24—H24C | 109.5 |
| H8B—C8—H8C | 109.5 | H24B—C24—H24C | 109.5 |
| O5—C9—O1 | 120.96 (9) | O12—C25—O8 | 123.29 (9) |
| O5—C9—C10 | 125.75 (9) | O12—C25—C26 | 126.46 (9) |
| O1—C9—C10 | 113.15 (9) | O8—C25—C26 | 110.18 (9) |
| C11—C10—C9 | 113.22 (8) | C25—C26—C30 | 110.55 (8) |
| C11—C10—C13 | 107.29 (8) | C25—C26—C29 | 108.29 (8) |
| C9—C10—C13 | 107.24 (8) | C30—C26—C29 | 111.02 (9) |
| C11—C10—C14 | 109.60 (9) | C25—C26—C27 | 108.45 (8) |
| C9—C10—C14 | 109.05 (8) | C30—C26—C27 | 111.08 (9) |
| C13—C10—C14 | 110.40 (8) | C29—C26—C27 | 107.34 (8) |
| O6—C11—C10 | 111.08 (8) | O13—C27—C26 | 110.17 (8) |
| O6—C11—H11A | 109.4 | O13—C27—H27A | 109.6 |
| C10—C11—H11A | 109.4 | C26—C27—H27A | 109.6 |
| O6—C11—H11B | 109.4 | O13—C27—H27B | 109.6 |
| C10—C11—H11B | 109.4 | C26—C27—H27B | 109.6 |
| H11A—C11—H11B | 108.0 | H27A—C27—H27B | 108.1 |
| O6—C12—O7 | 110.23 (8) | O14—C28—O13 | 110.38 (8) |
| O6—C12—C15 | 105.58 (9) | O14—C28—C32 | 105.13 (8) |
| O7—C12—C15 | 105.40 (8) | O13—C28—C32 | 105.60 (8) |
| O6—C12—C16 | 111.80 (8) | O14—C28—C31 | 111.89 (9) |
| O7—C12—C16 | 111.59 (9) | O13—C28—C31 | 111.58 (9) |
| C15—C12—C16 | 111.91 (9) | C32—C28—C31 | 111.90 (9) |
| O7—C13—C10 | 110.12 (8) | O14—C29—C26 | 109.88 (8) |
| O7—C13—H13A | 109.6 | O14—C29—H29A | 109.7 |
| C10—C13—H13A | 109.6 | C26—C29—H29A | 109.7 |
| O7—C13—H13B | 109.6 | O14—C29—H29B | 109.7 |
| C10—C13—H13B | 109.6 | C26—C29—H29B | 109.7 |
| H13A—C13—H13B | 108.2 | H29A—C29—H29B | 108.2 |
| C10—C14—H14A | 109.5 | C26—C30—H30A | 109.5 |
| C10—C14—H14B | 109.5 | C26—C30—H30B | 109.5 |
| H14A—C14—H14B | 109.5 | H30A—C30—H30B | 109.5 |
| C10—C14—H14C | 109.5 | C26—C30—H30C | 109.5 |
| H14A—C14—H14C | 109.5 | H30A—C30—H30C | 109.5 |
| H14B—C14—H14C | 109.5 | H30B—C30—H30C | 109.5 |
| C12—C15—H15A | 109.5 | C28—C31—H31A | 109.5 |
| C12—C15—H15B | 109.5 | C28—C31—H31B | 109.5 |
| H15A—C15—H15B | 109.5 | H31A—C31—H31B | 109.5 |
| C12—C15—H15C | 109.5 | C28—C31—H31C | 109.5 |
| H15A—C15—H15C | 109.5 | H31A—C31—H31C | 109.5 |
| H15B—C15—H15C | 109.5 | H31B—C31—H31C | 109.5 |
| C12—C16—H16A | 109.5 | C28—C32—H32A | 109.5 |
| C12—C16—H16B | 109.5 | C28—C32—H32B | 109.5 |
| H16A—C16—H16B | 109.5 | H32A—C32—H32B | 109.5 |
| C12—C16—H16C | 109.5 | C28—C32—H32C | 109.5 |
| H16A—C16—H16C | 109.5 | H32A—C32—H32C | 109.5 |
| H16B—C16—H16C | 109.5 | H32B—C32—H32C | 109.5 |
| C9—O1—C1—O2 | 3.46 (14) | C25—O8—C17—O9 | −55.71 (13) |
| C9—O1—C1—C2 | −179.97 (8) | C25—O8—C17—C18 | 128.37 (9) |
| O2—C1—C2—C5 | −3.88 (14) | O9—C17—C18—C19 | 164.90 (10) |
| O1—C1—C2—C5 | 179.70 (7) | O8—C17—C18—C19 | −19.41 (11) |
| O2—C1—C2—C6 | −126.13 (11) | O9—C17—C18—C21 | 47.51 (13) |
| O1—C1—C2—C6 | 57.46 (10) | O8—C17—C18—C21 | −136.79 (8) |
| O2—C1—C2—C3 | 112.47 (11) | O9—C17—C18—C22 | −72.37 (13) |
| O1—C1—C2—C3 | −63.95 (10) | O8—C17—C18—C22 | 103.33 (10) |
| C4—O4—C3—C2 | 56.70 (10) | C20—O11—C19—C18 | −55.78 (11) |
| C1—C2—C3—O4 | −171.01 (8) | C17—C18—C19—O11 | −62.23 (11) |
| C5—C2—C3—O4 | −54.14 (10) | C21—C18—C19—O11 | 55.16 (10) |
| C6—C2—C3—O4 | 67.10 (10) | C22—C18—C19—O11 | 175.83 (8) |
| C3—O4—C4—O3 | −56.64 (10) | C19—O11—C20—O10 | 53.54 (10) |
| C3—O4—C4—C7 | −170.13 (8) | C19—O11—C20—C23 | 167.00 (8) |
| C3—O4—C4—C8 | 68.19 (11) | C19—O11—C20—C24 | −70.62 (11) |
| C5—O3—C4—O4 | 57.13 (10) | C21—O10—C20—O11 | −55.42 (11) |
| C5—O3—C4—C7 | 170.65 (8) | C21—O10—C20—C23 | −168.54 (8) |
| C5—O3—C4—C8 | −67.37 (10) | C21—O10—C20—C24 | 69.31 (10) |
| C4—O3—C5—C2 | −57.84 (10) | C20—O10—C21—C18 | 58.32 (10) |
| C1—C2—C5—O3 | 170.98 (7) | C17—C18—C21—O10 | 65.26 (10) |
| C6—C2—C5—O3 | −66.48 (10) | C19—C18—C21—O10 | −55.93 (10) |
| C3—C2—C5—O3 | 54.57 (10) | C22—C18—C21—O10 | −176.18 (8) |
| C1—O1—C9—O5 | 57.23 (13) | C17—O8—C25—O12 | −5.51 (15) |
| C1—O1—C9—C10 | −126.81 (9) | C17—O8—C25—C26 | 177.25 (8) |
| O5—C9—C10—C11 | −168.32 (10) | O12—C25—C26—C30 | 121.38 (11) |
| O1—C9—C10—C11 | 15.95 (11) | O8—C25—C26—C30 | −61.49 (11) |
| O5—C9—C10—C13 | −50.17 (13) | O12—C25—C26—C29 | −0.44 (14) |
| O1—C9—C10—C13 | 134.10 (8) | O8—C25—C26—C29 | 176.69 (8) |
| O5—C9—C10—C14 | 69.39 (13) | O12—C25—C26—C27 | −116.62 (11) |
| O1—C9—C10—C14 | −106.34 (10) | O8—C25—C26—C27 | 60.51 (10) |
| C12—O6—C11—C10 | 56.87 (11) | C28—O13—C27—C26 | −56.55 (11) |
| C9—C10—C11—O6 | 63.78 (10) | C25—C26—C27—O13 | 171.20 (8) |
| C13—C10—C11—O6 | −54.34 (10) | C30—C26—C27—O13 | −67.12 (10) |
| C14—C10—C11—O6 | −174.23 (8) | C29—C26—C27—O13 | 54.41 (10) |
| C11—O6—C12—O7 | −55.71 (10) | C29—O14—C28—O13 | −55.94 (10) |
| C11—O6—C12—C15 | −169.06 (8) | C29—O14—C28—C32 | −169.37 (8) |
| C11—O6—C12—C16 | 69.02 (11) | C29—O14—C28—C31 | 68.96 (11) |
| C13—O7—C12—O6 | 56.53 (11) | C27—O13—C28—O14 | 55.42 (10) |
| C13—O7—C12—C15 | 170.01 (8) | C27—O13—C28—C32 | 168.54 (8) |
| C13—O7—C12—C16 | −68.31 (10) | C27—O13—C28—C31 | −69.66 (11) |
| C12—O7—C13—C10 | −57.49 (11) | C28—O14—C29—C26 | 57.59 (10) |
| C11—C10—C13—O7 | 54.30 (10) | C25—C26—C29—O14 | −171.68 (8) |
| C9—C10—C13—O7 | −67.63 (10) | C30—C26—C29—O14 | 66.78 (11) |
| C14—C10—C13—O7 | 173.69 (8) | C27—C26—C29—O14 | −54.79 (10) |
2,2,5-Trimethyl-1,3-dioxane-5-carboxylic anhydride (II). Hydrogen-bond geometry (Å, º)
| D—H···A | D—H | H···A | D···A | D—H···A |
| C3—H3B···O10i | 0.99 | 2.54 | 3.5043 (16) | 164 |
| C5—H5A···O9ii | 0.99 | 2.54 | 3.4723 (18) | 156 |
| C11—H11B···O10i | 0.99 | 2.57 | 3.5152 (17) | 161 |
| C14—H14A···O12iii | 0.98 | 2.56 | 3.531 (2) | 171 |
| C16—H16C···O3iv | 0.98 | 2.53 | 3.4973 (16) | 170 |
| C19—H19A···O7 | 0.99 | 2.53 | 3.5095 (17) | 168 |
| C27—H27A···O7 | 0.99 | 2.52 | 3.5035 (16) | 170 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, −y+1, −z+1; (iii) −x+2, −y+1, −z+1; (iv) x+1, y, z.
Funding Statement
This work was funded by American Chemical Society Petroleum Research Fund grant 53890-ND7 to J. A. Giesen.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Crystal structure: contains datablock(s) global, I, II. DOI: 10.1107/S2056989019016670/hb7867sup1.cif
Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989019016670/hb7867Isup2.hkl
Structure factors: contains datablock(s) II. DOI: 10.1107/S2056989019016670/hb7867IIsup3.hkl
13C and 1H NMR spectra. DOI: 10.1107/S2056989019016670/hb7867sup4.docx
Additional supporting information: crystallographic information; 3D view; checkCIF report