A Flexible Approach for the Asymmetric Synthesis of N-Protected (R)-5-Alkyl Tetramates and (R)-5-Alkyl Tetramic Acid Derivatives

A flexible two-step asymmetric approach to N-protected (R)-5-alkyl tetramates and (R)-5-alkyl tetramic acid derivatives is described. The method is based on the diastereoselective alkylation of (R)-phenylglycinol derived tetramates 7 and 8, which are the first synthetic equivalents to chiral nonracemic tetramate 5-carbanionic synthons A.