Enantioselective Total Synthesis of (+)-Gephyrotoxin 287C.

Abstract

A synthesis of (+)-gephyrotoxin 287C using (S)-phenylglycinol-derived tricyclic lactam 7 as the starting enantiomeric scaffold is reported. From the stereochemical standpoint, the key steps are the generation of the DHQ C-5 stereocenter by hydrogenation of the C-C double bond, removal of the chiral inductor to give a cis-DHQ, introduction of the DHQ C-2 substituent, completion of the (Z)-enyne moiety, and generation of the C-1 stereocenter during closure of the pyrrolidine ring.