First Michael addition reaction of α-substituted N-diphenylmethyleneglycinate with ethyl propiolate. Synthesis of α-substituted (E)-3,4-dehydroglutamic acids

Article abstract of DOI:10.1016/00404-0399(50)1149C-

(E)-α-substituted 3,4-dehydro glutamic acids 4, were prepared from ethyl N-diphenylmethyleneglycinate 5 by alkylation with a suitable alkyl halide followed by a Michael type addition reaction with ethyl propiolate, giving rise to a mixture of E/Z adducts 7/8. Sequential hydrolysis of the substituted glycine synthons 7/8 afforded the titled compounds 4 as single diastereomers.