(2S,4aR,6aR,7R,9S,10aS,10bR)-7-Carb-oxy-2-(3-fur-yl)-6a,10b-dimethyl-4,10-dioxoperhydro-benzo[f]isochromen-9-yl acetate

Acta Crystallogr Sect E Struct Rep Online. 2009 Feb 6;65(Pt 3):o471-2. doi: 10.1107/S1600536809002074.

Abstract

The asymmetric unit of the title compound, C(22)H(26)O(8), contains two crystallographically independent mol-ecules with closely comparable conformations (r.m.s. overlay = 0.54 Å for 30 non-H atoms). All six-membered rings display chair conformations, with a slight distortion for the lactone ring. The mol-ecules are connected by O-H⋯O hydrogen bonds into chains along [010], with the independent mol-ecules segregated into separate chains. The two mol-ecules in the asymmetric unit face each other in a head-to-tail fashion, with the furan ring of one mol-ecule turned towards the carboxylic acid terminal of the other mol-ecule.