A new strategy for the synthesis of hydroxylated pyrrolizidinic alkaloids by highly stereoselective indium-mediated allylation of pyrrolidinic aldehydes
作者:Isidoro Izquierdo、María T. Plaza、Víctor Yáñez
DOI:10.1016/j.tetasy.2005.10.010
日期:2005.11
Indium-mediated allylation of N-Cbz-L-prolinal 3, under Grignard conditions, was carried out with high yield and stereoselectivity (de = 90%) to afford intermediate (2S, 1'R)-N-benzyloxycarbonyl-2-(1'-hydroxybut-3'-en-1'-yl)pyrrolidine 4, which was transformed in two steps into (1R,3R,7aS)-1-hydroxy-3-hydroxymethylpyrrolizidine 9. Commercial Cbz-L-proline was a source of functionalization and chirality. (c) 2005 Elsevier Ltd. All rights reserved.