Total synthesis of (-)-haploscleridamine

Asymmetric total synthesis of the imidazole containing beta-carboline natural product, haploscleridamine, from histidine is described. Key to the successful assembly of this alkaloid is a ring-closing metathesis reaction of an imidazole derived allylic alcohol to construct a 3-piperidinone. Application of the Buchwald-modification of the classical Fischer indolization and deprotection of the N-tosyl moiety delivered haploscleridamine. (C) 2019 Published by Elsevier Ltd.