Progress toward the De Novo Asymmetric Synthesis of Euphanes

Abstract

Progress toward an asymmetric synthesis of euphanes is described. A C14-desmethyl euphane system possessing five differentially substituted and electronically distinct alkenes has been prepared. The route employed is based on sequential metallacycle-mediated annulative cross-coupling, double asymmetric Brønsted acid mediated intramolecular Friedel–Crafts alkylation, and an oxidative rearrangement to establish the requisite C10 quaternary center. These studies have also led to the discovery of a novel euphane-based modulator of the Liver X Receptor.

Toward the Asymmetric Synthesis of Cardenolides and Related Steroidal Systems: syn-SN2′ of Organometallics with C14–C17 Vinylepoxides

“…Unfortunately, this concise and convergent synthesis strategy delivers steroidal products that lack substitution at C17 ( 7 and 8 ). While enynes related to 5 that contain a substituted C17 carbon can be employed in this sequence of bond-forming events, such enynes currently require many additional chemical steps to prepare . As such, it was reasoned that late stage introduction of varied C17-substituents to species related to 7 or 8 would be strategically beneficial.…”