Towards the total synthesis of Daphniyunnine B

Abstract

This thesis describes the development of a series of synthetic routes towards the first synthesis of Daphniyunnine B, a Daphniphyllum alkaloid, utilising novel reactions and cascades. Studies began with an envisaged enantioselective Michael cascade reaction, which alternatively gave rise to a novel, efficient Michael-aldol cascade reaction affording perhydroindole structures in moderate to excellent diastereoselectivity.The enantioselective synthesis of the methyl-substituted core of Daphniyunnine B was achieved via an initial highly enantioselective organocatalytic Michael addition followed by a stereoselective organocatalytic intramolecular Michael addition.The stereocontrolled synthesis of the AC bicyclic core of (±) Daphniyunnine B was achieved via a quaternisation cyclisation approach.The stereocontrolled synthesis of the ACD tricyclic core of (±) Daphniyunnine B was achieved via an intramolecular Diels-Alder fragmentation reaction. Preliminary studies of an enantioselective variant are encouraging.

Date of Award	1 Aug 2011
Original language	English
Awarding Institution	The University of Manchester
Supervisor	David Procter (Supervisor)