A novel synthesis of γ-carboxy-L-glutamic acid from L-5-oxoproline esters (Amino acids ; 8)

Abstract

N-Alkyl-L-5-oxoproline esters L-5 react with phosgene to form primarily the α-chloro enamines 6, which then react further to give the 4-carboxylated compounds 7. Solvolysis of the latter with an alcohol furnishes the alkyl N-alkyl-4-(alkoxycarbonyl)-L-5-oxoprolina 2L,4DL-8 in good yields. The dibenzyl N-benzhydryl ester 2L , 4L - 8 c can be converted simply to γ-carboxyglutamic acid (L-Gla) by way of the N-Boc-protected dibenzyl ester 2L,4DL-10.