Tetrahedron letters

New strategy for the synthesis of 3-substituted prolines

P Karoyan, G Chassaing

Index: Karoyan, Philippe; Chassaing, Gerard Tetrahedron Letters, 1997 , vol. 38, # 1 p. 85 - 88

Full Text: HTML

Citation Number: 73

Abstract

Ring formation involving a 5-exo trig cyclization between a zinc enolate and a non activated double bond led to cis diastereoisomer of 3-substituted prolines. This cyclization was achieved with transfer of chirality onto the C-2 carbon when nitrogen was protected by an α- methylbenzyl group. Reprotonation of the lithium enolate of cis derivative yielded the trans diastereoisomer.