Synthesis of 1-Azaspirocycles via Lewis Acid-Mediated Spirocyclization of Cyclic N-Acyl-N,O-acetals
作者:Toshimasa Ito、Naoki Yamazaki、Chihiro Kibayashi
DOI:10.1055/s-2001-17475
日期:——
A new approach to 1-azaspirocycles has been developed starting from cyclic N-acyl-N,O-acetals. This sequence involves olefin-iminium cyclization mediated by Lewis acids leading to the spirocyclization products including the chlorinated products and the olefinic products. Mixtures of these products underwent catalytic hydrogenation and reductive dechlorination to produce the 1-azaspirans.