Sipeimine, a steroidal alkaloid from Fritillaria roylei Hooker.

In the title compound, 3,20-dihydroxycevan-6-one, C 27 H 43 NO 3 , all the six-membered rings have normal chair conformations except ring D, which exists in a twist-chair conformation. The five-membered ring C adopts an envelope conformation. An O-H…O hydrogen bond connects the molecules into spirals, which run along the b-axis direction.