Synthesis of pyrrolizidines via copper(I) catalyzed radical atom transfer cyclization
作者:Julio A. Seijas、M.Pilar Vázquez-Tato、Luis Castedo、Ramón J. Estévez、M.Gabriela Ónega、Maria Ruíz
DOI:10.1016/s0040-4020(01)88722-6
日期:1992.2
Trachelanthamidine and pseudoheliotridane are synthesized from 2S)-N-trichlkoroacetyl-2-vinylpyrrolidine (5) by a 5-exo-trig radical cyclization. The intermediate radical is generated heating 5 in a sealed tube (CH3CN/ 160-degrees-C) using CuCl as catalyst and the cyclization occurs in very good yield (93%). Cyclized product 6 is transformed either into (-)-trachelanthamidine (55% yield from 5) or into (-)-pseudoheliotridane (42% yield from 5).