(23 R ,23 1 S ,25 S )-23 1 ,26-Ep-oxy-23-ethyl-furost-20(22)-en-3β-ol.

The title compound, C 29 H 46 O 3 , is a steroid synthesized through a rearrangement of a sarsasapogenin derivative in acidic medium. The newly formed ring F is a tetra-hydro-2 H -pyran heterocycle substituted by two methyl groups placed in equatorial positions. This ring displays a chair conformation, while di-hydro-furan ring E , to which it is bonded, has an envelope conformation. The mol-ecules are associated by weak O-H⋯O hydrogen bonds to form chains running in the [101] direction in the crystal.