Synthesis of All Possible Isomers Corresponding to the Proposed Structure of Montanacin E, and Their Antitumor Activity

摘要

Total synthesis of 4 and its three diastereomers is described.The key steps involve stereoselective formation of the tetrahydrofuran ring by a cascade cyclization of hydroxy tosylate 7 and an intermolecular cross metathesis between a tetrahydrofuran 5 and a -lactone 6. Spectroscopic data of 4 and biosynthetic hypothesis strongly suggest it to be montanacin E. Inhibitory activities of 4 and its isomers against six human solid tumor cell lines were also evaluated.