Benzyl 5-hy­droxy-4-oxapenta­cyclo­[5.4.1.02,6.03,10.08,11]dodecane-3-carboxyl­ate

Rajshekhar Karpoormath; Tricia Naicker; Thavendran Govender; Hendrik G Kruger; Glenn E M Maguire

doi:10.1107/S1600536811009020

. 2011 Mar 12;67(Pt 4):o877. doi: 10.1107/S1600536811009020

Benzyl 5-hydroxy-4-oxapentacyclo[5.4.1.0^2,6.0^3,10.0^8,11]dodecane-3-carboxylate

Rajshekhar Karpoormath ^a, Tricia Naicker ^b, Thavendran Govender ^b, Hendrik G Kruger ^a, Glenn E M Maguire ^a,^*

PMCID: PMC3100052 PMID: 21754154

Abstract

The title compound, C₁₉H₁₈O₄, exhibits a long C—C bond [1.575 (2) Å] in the cage structure. In the crystal, pairs of O—H⋯O hydrogen bonds link the molecules into centrosymmetric dimers. C—H⋯O interactions also occur.

Related literature

For examples of PCU cage structures that exhibit C—C bond lengths that deviate from the normal value, see: Flippen-Anderson et al. (1991) ▶; Linden et al. (2005 ▶). For similar structures, see: Kruger et al. (2005 ▶, 2006 ▶); Karpoormath et al. (2010 ▶).

Experimental

Crystal data

C₁₉H₁₈O₄
M _r = 310.33
Monoclinic,
a = 6.5254 (2) Å
b = 12.8995 (2) Å
c = 16.9772 (5) Å
β = 95.243 (1)°
V = 1423.07 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 173 K
0.34 × 0.22 × 0.16 mm

Data collection

Nonius KappaCCD diffractometer
6925 measured reflections
3540 independent reflections
2930 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.119
S = 1.06
3540 reflections
212 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.47 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: COLLECT (Nonius, 2000 ▶); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997 ▶); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: OLEX2 (Dolomanov et al., 2009) ▶; software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811009020/is2678sup1.cif

e-67-0o877-sup1.cif^{(22.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811009020/is2678Isup2.hkl

e-67-0o877-Isup2.hkl^{(173.6KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2ⁱ	0.97 (2)	1.91 (2)	2.8561 (16)	164 (2)
C3—H3⋯O1ⁱⁱ	1.00	2.46	3.3716 (18)	151
C10—H10⋯O3ⁱⁱⁱ	1.00	2.41	3.3840 (19)	163

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

Acknowledgments

The authors would like to thank Dr Hong Su from the University of Capetown for the data collection and structure refinement.

supplementary crystallographic information

Comment

We have reported the single-crystal X-ray structure of a range of pentacycloundecane (PCU) derivatives. More recently this included an ether diol (Kruger et al., 2005), a mono-ketone ethyl acetate (Kruger et al., 2006) and a mono-ketone diester (Karpoormath et al., 2010). The tile compound is the first example of a PCU derivative X-ray structure report containing an ether, ester and primary alcohol functional groups (Fig. 1). In the crystal, the ether oxygen hydrogen bonds to the primary alcohol group of its nearest neighbour (O1—H1···O2). This arrangement forms centrosymmetric dimers (Fig. 2).

Experimental

A mixture of 5-hydroxy-4 oxahexacyclo[5.4.0.0^2,6.0^3,10.0^5,9]dodecane-3-carboxylic acid (1 g, 4.5 mmol), benzyl bromide (6 ml, 4.95 mmol) and K₂CO₃ (1.86 g, 13.5 mmol) in DMF (5 ml), was heated to 120 °C and stirred for 5 h. The reaction mixture is cooled to room temperature and diluted with 50 ml of water and stirred further for 10 min. The resulting aqueous reaction mixture was then extracted with dichloromethane (25 ml × 2). The organic layer was dried with anhydrous Na₂SO₄, filtered, and concentrated under vacuum. Chromatography with hexane–EtOAc (5:1) afforded products a colourless oil (1.1 g, 79%). Crystallization of the product was carried out by dissolving the pure compound in 2 ml solvent mixture of ethyl acetate and hexane (1:5) and storing the solution at 18 °C (m.p. 397–398 K).

¹H NMR (CDCl₃, 400 MHz) δ p.p.m.: 1.55 (1.0H, d, J=10.69 Hz), 1.89 (1.0H, d, J=10.65 Hz), 2.59–2.67 (4.0H, m,), 2.73–2.77 (2.0H, m), 2.97–3.06 (2.0H, m), 4.20 (1.0H, s), 5.19 (2.0H, q, J=11.55 Hz), 7.28–7.33 (5.0H, m).

¹³C NMR (CDCl₃, 100 MHz) δ p.p.m.: 31.12, 42.10, 42.78, 43.44, 43.52, 46.66, 47.50, 49.88, 57.16, 59.31, 66.82, 89.89, 119.00, 128.24, 128.46, 128.75, 135.77, 171.32, 207.32.

IR (neat) V_max cm^-1: 3430.37, 2961.81, 1739.32, 1453.93, 1336.94, 1267.97, 1199.80, 1137.26, 1091.29, 1078.22, 902.84, 734.29, 692.33, 542.17 cm^-1.