Synthetic studies on virantmycin .2. Total synthesis of unnatural (+)-virantmycin and determination of its absolute stereochemistry

The enantioselective total synthesis of (+)-virantmycin (1) has been achieved by means of the Sharpless asymmetric epoxidation of allylic alcohol 27 followed by an intramolecular epoxide opening of the exo epoxy alcohol 32 which was derived from the endo epoxy alcohol 28. The synthesis of (+)-1 has established that the absolute configuration of the natural product (-)-1 is shown to be 2R, 3R at the two chiral centers. Further, antiviral activities of the virantmycin analogs were also examined against influenza virus. Copyright (C) 1996 Elsevier Science Ltd