A smooth rearrangement of N-p-toluenesulfonyl 2-tert-butyldiphenylsilylmethyl-substituted azetidines into N-p-toluenesulfonyl 3-tert-butyldiphenylsilyl-substituted pyrrolidines

摘要: The rearrangement of N-p-toluenesulfonyl 2-tert-butyldiphenylsilylmethyl-substituted azetidines into 3-tert-butyldiphenylsilyl-substituted pyrrolidines under Lewis acid conditions in dichloromethane involves 1,2-migration silicon through a siliranium ion. formation ion was discovered not to be concert with σC–N cleavage from stereochemical analysis the pyrrolidine products formed 3- and 4-substituted-2-tert-butyldiphenylsilylmethyl also optical rotation data chiral HPLC product 2(R)-tert-butyldiphenylsilylmethyl azetidine. sterically less hindered is followed by its SN2 opening internal nitrogen nucleophile. Oxidative σC–Si bond leads 3-hydroxypyrrolidines.