Crystal structure of 3a,6,6,9a-tetra­methyl­dodeca­hydro­naphtho­[2,1-b]furan-2-ol

Xin-Wei Shi; Sheng-Kun Li; Dang-Dang Li; Qiang-Qiang Lu

doi:10.1107/S2056989015016370

. 2015 Sep 12;71(Pt 10):o710–o711. doi: 10.1107/S2056989015016370

Crystal structure of 3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan-2-ol

Xin-Wei Shi ^a, Sheng-Kun Li ^b,^*, Dang-Dang Li ^b, Qiang-Qiang Lu ^a

PMCID: PMC4647384 PMID: 26594436

Abstract

The title compound (common name: sclaral), C₁₆H₂₈O₂, is a sclareolide derivative, which was synthesized from sclareolide itself. In the molecule, the two six-membered rings, A and B, of the labdane skeleton adopt chair conformations and the five-membered O-containing heterocyclic ring C displays an envelope conformation, with the methine C atom of the fused C—C bond as the flap. In the crystal, molecules are linked by O—H⋯O hydrogen bonds, forming chains propagating along [100].

Keywords: crystal structure, sclareolide, sclaral, hydrogen bonding

Related literature

For the chemistry and biological importance of sclareolides and the title compound, see: Dixon et al. (2012 ▸); Michaudel et al. (2015 ▸); Sun et al. (2013 ▸). For previously reported spectroscopic and analytical data for the title compound, see: Margaros et al. (2007 ▸). For related structures, see: Martínez-Carrera et al. (1978 ▸); Huang et al. (2008 ▸). graphic file with name e-71-0o710-scheme1.jpg

Experimental

Crystal data

C₁₆H₂₈O₂
M _r = 252.38
Orthorhombic,
a = 7.1675 (8) Å
b = 11.2654 (13) Å
c = 18.144 (2) Å
V = 1465.0 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 296 K
0.22 × 0.20 × 0.18 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2002 ▸) T _min = 0.984, T _max = 0.987
9607 measured reflections
2658 independent reflections
2299 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.127
S = 1.08
2658 reflections
181 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.40 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: SMART (Bruker, 2002 ▸); cell refinement: SAINT (Bruker, 2002 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: SHELXTL (Sheldrick, 2008 ▸) and PLATON (Spek, 2009 ▸); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S2056989015016370/su5201sup1.cif

e-71-0o710-sup1.cif^{(15.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015016370/su5201Isup2.hkl

e-71-0o710-Isup2.hkl^{(130.6KB, hkl)}

Click here for additional data file.^{(2.9KB, cdx)}

Supporting information file. DOI: 10.1107/S2056989015016370/su5201Isup3.cdx

Click here for additional data file.^{(6.4KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015016370/su5201Isup4.cml

Click here for additional data file.^{(1.5MB, tif)}

. DOI: 10.1107/S2056989015016370/su5201fig1.tif

A view of the molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 30% probability level.

Click here for additional data file.^{(1.9MB, tif)}

a . DOI: 10.1107/S2056989015016370/su5201fig2.tif

View along the a axis of the crystal packing of the title compound. The hydrogen bonds are shown as dashed lines (see Table 1), and C-bound H atoms have been omitted for clarity.

CCDC reference: 1421899

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
O2H1OO1ⁱ	0.93(2)	1.90(2)	2.773(2)	155(3)

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Symmetry code: (i) Inline graphic .

Acknowledgments

This project was supported by the National Natural Science Foundation of China (Nos. 3140177 and 31200257), the West Light Foundation of The Chinese Academy of Sciences (No. 2012DF05), and the National Science Foundation of Jiangsu Province (No. BK20140684).

supplementary crystallographic information

S1. Comment

The title compound, sclaral, is an important reaction intermediate in the synthesis of some natural products. It is used as a precursor of borono-sclareolide which makes the direct coupling of a terpenoid "donor" with a non-terpenoid "acceptor" possible (Dixon et al., 2012). It is also used to produce analogs of hongoquercin A, an antibiotic of fungal origin (Michaudel et al., 2015; Sun et al., 2013). Moreover, sclaral is an intermediate in the production of important natural products, such as (+)-premnalane A (Margaros et al., 2007). The title compound has been synthesized and we report herein on its crystal structure,

The molecular structure of the title compound is shown in Fig. 1. The molecule possesses a highly rigid structure, composed of three main rings (A/i>, B and C). The six-membered rings, A/i> (C5/C6/C8—C11) and B (C1—C6), adopt chair conformations, while the five-membered O-containing heterocyclic ring C (C1/C2/C14/C15/O1) displays an envelope conformation, in which atom C1 is the flap.

In the crystal, molecules are linked via O—H···O hydrogen bonds forming chains propagating along the a axis direction (Table 1 and Fig. 2).

S2. Synthesis and crystallization

A solution of (+)-sclareolide (10.0 g, 40.0 mmol,1.0 eq) in CH₂Cl₂ (100ml) was cooled to 195 K and DIBAL-H (1.5M in toluene,32ml, 48.0 mmol, 1.2 eq) was added drop wise over 20 min, and stirring was continued for an additional 60 min. Water was then slowly added until the bubbles vanished then the temperature of the mixture was allow to rise to rt. the mixture was stirred at rt for 30min, and then extracted with CH₂Cl₂ (3 × 100 ml). The combined organic extracts were washed with saturated aqueous NaHCO₃ solution (3 × 50 ml) and washed with brine (3 × 50 ml), dried over MgSO₄, filtered and concentrated under reduced pressure, affording the title compound, sclaral (yield: 9.37 g, 93 %, 3.7:1 lactol:aldehyde) as a white solid. Spectroscopic and analytical data matches reported previously (Margaros et al., 2007). The white solid was recrystallized from EtOH to afford colourless crystals.

S3. Refinement

The CH H atoms (H1, H5 and H15) and the hydroxyl H atom (H1O) were located in a difference Fourier map. The CH H atoms were freely refined while the OH H atom was refined with U_iso(H) = 1.5U_eq(O). The remaining C-bound H atoms were placed in calculated positions and refined as riding: C—H = 0.96-0.97 Å with U_iso(H) = 1.5U_eq(C) for methyl H atoms and 1.2U_eq(C) for other H atoms.