(IUCr) Crystallography Journals Online

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Acta Cryst. (2009). E65, o1540 [ doi:10.1107/S1600536809020960 ]

A 3,5-dinitrobenzoyl derivative of a stereoisomer of glycerol menthonide

A. Kiessling, C. Campana and M. E. Kastner

Abstract: The title compound, [(2S,5R,6S,9R)-6-isopropyl-9-methyl-1,4-dioxaspiro[4.5]dec-2-yl]methyl 3,5-dinitrobenzoate, C₂₀H₂₆N₂O₈, was synthesized as part of a study of three-carbon stereochemical systems. The crystallographic assignment of the absolute stereochemistry is consistent with having started with (-)-menthone, the acetal carbon is R and the secondary alcohol is S. This brings the dinitrobenzoate into approximately the same plane as the menthyl ring and anti to the isopropyl group. Close intermolecular C=ONO₂ contacts between neighboring molecules [2.8341 (16) Å] contribute to the packing arrangement. The structure was refined as a pseudo-merohedral twin (monoclinic space group P2₁ emulating the orthorhombic space group C222₁). Application of the twin law 100, 0 $\\overline{1}$ 0, $\\overline{1}$ 0 $\\overline{1}$ gave a 2:1 ratio of twin moieties [refined BASF value = 0.3790 (7)].

Online 10 June 2009