Enantioselective tandem oxy-copeene reaction

Abstract

The tandem oxy-Cope/ene reaction allows the rapid construction of complex structures in a few steps. It was notably used in the total synthesis of (+)-arteannium M where the cascade revealed to be highly diastereoselective and enantioselective. The hypothesis that the retention of chirality based on the rigidity of an intermediate atropisomer devoid of stereogenic centers was proposed. This document presents a study of the enantioselectivity of the tandem oxy-Cope/ene reaction and provides an explanation for the decrease in chirality observed during the cascade. Different variables of the reaction and of the starting material were analyzed to explain the retention of chirality.* The efforts of our group in the development of tandem reactions led to the discovery of a novel cascade that involves 4 pericyclic reactions: the oxa-Cope/Claisen/ene/Claisen cascade. This sequence of reactions was briefly investigated to determine its scope and limitations, notably by changing the substituent on the alkyne and on the tertiary alcohol of 150*. *Please refer to dissertation for diagrams.