Norbornane-exo-cis-2,3-diyl 1′,2′-phenyl­ene orthocarbonate

Richard Betz; Peter Klüfers

doi:10.1107/S1600536807063660

. 2008 Jan 9;64(Pt 2):o399. doi: 10.1107/S1600536807063660

Norbornane-exo-cis-2,3-diyl 1′,2′-phenylene orthocarbonate

Richard Betz ^a, Peter Klüfers ^a,^*

PMCID: PMC2960339 PMID: 21201427

Abstract

The title compound (systematic name: 4,7-methano-2,2′-spirobi[1,3-benzodioxole]), C₁₄H₁₄O₄, is an asymmetric spiro ester of orthocarbonic acid and two diols, viz. the aromatic benzene-1,2-diol and the aliphatic vicinal norbornane-exo-cis-2,3-diol. The orthocarbonate molecule is close to having non-crystallographic C _s symmetry. The five-membered ring stemming from the aliphatic diol has an envelope conformation. C—O bonds including the spiro-C atom span an approximately 0.07 Å range, but are within 0.02 Å of the respective distances in a density functional theory calculation, i.e. the distance difference is not caused by packing forces. Accordingly, the crystal packing is characterized by weak C—H⋯O and C—H⋯π interactions.

Related literature

For the synthesis of the title compound, see: Komatsu et al. (1992 ▶). For related compounds, see: Betz & Klüfers (2007a ▶,b ▶,c ▶); Betz et al. (2007 ▶). Density functional theory calculations were performed by Betz & Klüfers (2008 ▶).

Experimental

Crystal data

C₁₄H₁₄O₄
M _r = 246.25
Monoclinic,
a = 7.9125 (3) Å
b = 9.5545 (5) Å
c = 15.2813 (6) Å
β = 101.490 (3)°
V = 1132.11 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 200 (2) K
0.30 × 0.25 × 0.16 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: none
8399 measured reflections
2582 independent reflections
1716 reflections with I > 2σ(I)
R _int = 0.054

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.119
S = 1.05
2582 reflections
164 parameters
Only H-atom displacement parameters refined
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: COLLECT (Nonius, 2004 ▶); cell refinement: SCALEPACK (Otwinowski & Minor 1997 ▶); data reduction: DENZO (Otwinowski & Minor 1997 ▶) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: PLATON (Spek, 2003 ▶; 2006 version).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807063660/lx2027sup1.cif

e-64-0o399-sup1.cif^{(18KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807063660/lx2027Isup2.hkl

e-64-0o399-Isup2.hkl^{(126.8KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

O1—C1	1.367 (2)
O2—C1	1.370 (2)
O3—C1	1.412 (2)
O4—C1	1.435 (2)

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Table 2. Hydrogen-bond geometry (Å, °).

Cg is the centroid of the C9–C14 phenylene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O4ⁱ	1.00	2.71	3.623 (2)	151
C7—H7A⋯O4ⁱ	0.99	2.76	3.663 (2)	151
C14—H14⋯O2ⁱⁱ	0.95	2.61	3.501 (2)	156
C14—H14⋯O4ⁱⁱ	0.95	2.88	3.514 (2)	125
C2—H2⋯Cgⁱⁱⁱ	1.00	2.86	3.563 (2)	128
C5—H5⋯Cg^iv	1.00	2.66	3.568 (2)	152

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

The authors thank Moritz Reichvilser for professional support.

supplementary crystallographic information

Comment

The title compound was prepared in order to compare its NMR-spectroscopic data with those of related silicon compounds.

In the molecule, a central carbon atom is chelated by a phenylene-1,2-dioxy and a norbornylene-exo-cis-2,3-dioxy moiety. The C—O bond lengths differ markedly (1.37 to 1.44 Å). About the same bond-length values were computed for the isolated molecule on the B3LYP/6–31+G(d,p) level of theory thus ruling out packing forces as the origin of the bond-length differences. The five-membered chelate ring stemming from the aliphatic diol adopts an envelope conformation on the spiro center C1 (puckering parameters: Q₂ = 0.1274 (16) Å, φ₂ = 42.6 (7)° for the O1—C1—O2—C4—C3 ring).

Accordingly, the crystal packing is characterized by weak C—H···X interactions whose H···X distances are close to the sum of the van-der-Waals radii (vdWr). In terms of the vdWr criterion, the shortest tabulated hydrogen-bond, the C14—H14···O2 interaction, is 0.11 \&A shorter than the radii sum. The weak interactions in (I) are thus less significant than those in the related 1-(ylomethyl)cyclopentyl 1',2'-phenylene orthocarbonate, where C—H···O bonds are observed at the radii sum minus 0.35 Å (Betz & Klüfers, 2007c). Fig. 2 shows this interaction as well as the shortest C—H···π bond which has one of the norbornane-bridgehead C—H functions as the donor. The other bridgehead methylidyne function acts as a donor in a still weaker bond. Moreover, another weak C—H···O bond may be recognized with a diol-CH function as the donor (see the hydrogen bond table).

Experimental

The title compound was prepared based on a published procedure (Komatsu et al., 1992) upon reaction of norbornane-exo-cis-2,3-diol with 2,2-dichlorobenzo[1.3]dioxol in dichloromethane in the presence of pyridine. Crystals suitable for X-ray analysis were obtained after recrystallization from boiling ethyl acetate.