[1R-(1α,2α,4α,5β,6α,7α)]-4-Benzoyl-oxymethyl-5,6-dihy-droxy-3,8-dioxa-tricyclo-[5.1.0.0]octan-5-yl acetate (3-deacetyl-crotepoxide) from Kaempferia rotunda Val

Acta Crystallogr Sect E Struct Rep Online. 2010 Oct 30;66(Pt 11):o2945. doi: 10.1107/S1600536810042686.

Abstract

The title compound, C(16)H(16)O(7), isolated from Kaempferia rotunda rhizomes, features a six-membered cyclo-hexane ring that adopts a twisted-boat conformation owing to the presence of two adjacent epoxide attachments that lock in four of the six axial positions. The CH(3)CO(2)- and HO- substituents occupy equatorial positions. However, the bond angles at the ring carbon connected to the C(6)H(5)CO(2)CH(2)- substituent deviate signifcantly from the idealized tetra-hedral angles as the carbon atom is part of an epoxide ring. In the crystal, the molecules are linked into chains by O-H⋯O hydrogen bonds.