One-pot stereospecific synthesis of 8a-hydroxy- and 8a-alkoxy-2,2,8-trisubstituted-3-oxoindolizidines. Mechanistic studies on the elaboration of the 8a-substituted indolizidine ring
作者:María José Domínguez、María Teresa García-López、Rosario González-Muñiz
DOI:10.1016/s0040-4020(01)81910-4
日期:1993.1
Stereospecific solvent-dependent synthesis of 8a(R)-alkoxy-8(S)-tert-butyloxycarbonyl-amino-2(S)-benzyl-3-oxoindolizidine-2-carboxylic acid or the corresponding methyl 8a(S)-hydroxy-2-carboxylate derivative by hydrogenation of a conveniently protected α-benzyl-γ-ketodiester derived from ornithine, is described. The formation of an hemiaminal is proposed to rationalize the stereospecificity in the generation