IMPROVED SYNTHESES OF THE FR900482 AND MITOMYCIN BENZAZOCINE RING CORE VIA MITSUNOBU CYCLIZATION

摘要

An asymmetric synthesis of a highly functionalized benzazocine core of FR900482 and the mitomycins has been achieved in 20 and 19 steps,respectively.Key features of the synthesis include a highly chemoselective reduction of a nitro group and a Mitsunobu cyclization using either sulfonamides or carbamates.Removal of the protecting groups afforded the free benzazocine.