Asymmetric total synthesis of (+)-equilenin utilizing two types of cascade ring expansion reactions of small ring systems
Abstract
Enantioselective synthesis of (+)-equilenin 1 utilizing two types of cascade ring expansion reactions of small ring systems is described. The first key step is an asymmetric epoxidation–ring expansion reaction of cyclopropylidene derivatives to afford chiral cyclobutanones. We found that both the