A Convenient Synthesis of 3,3-Dichloroazetidines, a New Class of Azetidines.
A short synthesis of appropriately substituted 3,3-dichloroazetidines, a virtually unknown class of azetidines, is described. The reaction of 3,3-dichloro-1-azaallylic carbanions, generated from N-(1-aryl-2,2-dichloroethylidene)amines, with aromatic aldehydes produced alpha,alpha-dichloro-beta-hydroxy imines that, upon treatment with mesyl chloride, were converted into the corresponding beta-(mesyloxy) imines. Reaction of these alpha,alpha-dichloro-beta-(mesyloxy) ketimines with potassium cyanide or sodium borohydride in methanol furnished a variety of 2-cyano- and 2-methoxy-3,3-dichloroazetidines in a stereoselective manner. Reduction of beta-(mesyloxy) imines with sodium cyanoborohydride followed by cyclization with potassium carbonate in DMSO yielded 3,3-dichloroazetidines as well.
Aelterman
Wim
W
Laboratoire de Chimie Physique et de Cristallographie, Université Catholique de Louvain, 1, Place Louis Pasteur, B-1348 Louvain-la-Neuve, Belgium.
De Kimpe
Norbert
N
Declercq
Jean-Paul
JP