FORMATION OF THE C3-C4 UNSATURATED FRAMEWORK OF CRIBROSTATIN 4 VIA DEAD-MEDIATED OXIDATION OF AN ALLYLIC TERTIARY AMINE

摘要

The formal synthesis of the tetrahydroisoquinoline alkaloid cribrostatin 4(1)is described.The synthesis features as a key step a DEAD-mediated oxidation of an allylic tertiary amine to an iminium ion immediately followed by a Pictet-Spengler cyclization to form the pentacyclic skeleton of cribrostatin 4.