Synthesis of Optically Pure 2-Azetidinones Having <i>N</i>-Dehydroamino Acid Side-Chains
作者:Benito Alcaide、Concepción Polanco、Miguel A. Sierra
DOI:10.1055/s-1998-1667
日期:1998.4
An efficient, three step synthesis of optically pure N-vinyl-2-azetidinones 1 starting from α- or β-amino ester imines has been developed. Staudinger reaction between amino ester derived imines and ketene precursors gave 2-azetidinones 2. Enolate formation on the amino ester moiety of the optically pure 2-azetidinones 2, selenylation and, finally, MCPBA treatment afforded N-vinyl-2-azetidinones 1 in good to excellent yields, with total retention of the stereochemistry of the starting material. Compounds 2 bear the functionality needed to place a carboxy group contiguous to the lactam nitrogen, a structural feature common to all the active β-lactam antibiotics.