[1R-(1α,2α,4α,5β,6α,7α)]-4-Benzoyloxymethyl-5,6-dihydroxy-3,8-dioxatricyclo[5.1.0.02,4]octan-5-yl acetate (3-deacetylcrotepoxide) from Kaempferia rotunda Val.

Abstract

The title compound, C16H16O7, isolated from Kaempferia rotunda rhizomes, features a six-membered cyclohexane 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 CH3CO2– and HO– substituents occupy equatorial positions. However, the bond angles at the ring carbon connected to the C6H5CO2CH2– substituent deviate signifcantly from the idealized tetrahedral 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.