Synthesis and reactions of esters of N-hydroxyphthalimide and N-protected amino acids

Esters can be prepared from N-hydroxyphthalimide and N-carbobenzoxy- or N-phthaloyl-amino acids using dicyclohexylcarbodi-imide as condensing agent. The compounds are suitable for the stepwise synthesis of peptides without racemization. With methanol the N-hydroxyphthalimide ester of N-phthaloylglycine can be converted into the methyl ester of N-phthaloylglycine.