Novel direct rearrangement of a 9β,11β-epoxylanostan-7-one into a B-homo-derivative with incorporation of the C-10 angular methyl group
Abstract
The rearrangement by boron trifluoride–diethyl ether of 3β-acetoxy-9β,11β-epoxylanostan-7-one (2) leads to the ring B enlarged product (3) as well as to the cucurbitane derivatives (1), (4a), and (4b).