Intramolecular 1,5-hydrogen atom transfer radical reaction of pyrrolidine derivatives

Intramolecular 1,5-hydrogen atom transfer radical cyclization reaction of p yrrolidine derivatives was examined. Radical reaction of 3,4-bis(alpha,beta -unsaturated acyloxy)-(8, 9) and 3,4-diacetoxy (13) -N-[(o-halobenzyl)pyrro lidines underwent elimination of two acyloxy groups to give mainly N-benzyl pyrrole (11). On the other hand, the similar reaction of 3,4-diallyloxy-N-( o-bromobenzyl)pyrrolidine (16) gave desired hexahydrofuro[3,2-b]pyrroles (1 7, 18) together with a dimeric hexahydrofuro[3,2-b]pyrrole (19).