PROCESSES AND INTERMEDIATES FOR THE PREPARATION OF N-(S-3-ALKYL-HEPTANOYL)-D-GAMMA-GLUTAMYL-GLYCYCL-D-ALANINE

摘要

acid and analogues of formula (I) are new. R is CH2OR1, CH2OH, CHO, COOH or COCl or another activated form of the acid COOH; R1 is H or silyl hydroxy protecting gp. Alanine derivs. of formula (II) and their cationic salts when R2 and R3 are H are new. R2=R3=H; pr R2,R3=1-6C alkyl, 6-8C cycloalkylmethyl or benzyl. Prepn. of an acid or ester of formula (III) comprises coupling an activated form of (I) with an amino acid ester of formula (IV) to form a cpd. (II), followed by hydrogenation to reduce the double bond and remove the benzyl gp.(s). R4=R5=H; or one=H and the other=1-6C alkyl or 6-8C cycloalkylmethyl; R6=R7=PhCH2; or one of R6 and R7=PhCH2 and the other=1-6C alkyl or 6-8C cycloalkylmethyl.