[4+2] cycloadditions of iminoacetonitriles : a general strategy for the synthesis of quinolizidines, indolizidines, and piperidines

Abstract

Iminoacetonitriles participate as reactive dienophiles in intermolecular and intramolecular Diels-Alder cycloadditions leading to quinolizidines, indolizidines, and piperidines. The resultant a-amino nitrile cycloadducts are versatile synthetic intermediates which can be further elaborated by stereoselective alkylation, reduction, reductive cyclization, and Bruylants reactions. The first part of this thesis describes the full details of our studies on the synthesis of iminoacetonitriles, the scope of their Diels-Alder reactions, and the synthetic elaboration of the a-amino nitrile cycloadducts to provide access to a variety of substituted quinolizidine and indolizidine derivatives. The second part of this thesis reports on the total synthesis of quinolizidine (-)-217A and our efforts directed toward the total synthesis of indolizidine (-)-235B'.