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

Article abstract of DOI:10.1016/S0040-4020(01)81910-4

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-