The t-butyl esters of amino acids are useful carboxylprotecting groups in peptide synthesis because they are cleaved readily by acids. The esters have been prepared from N-acylated amino acids by reaction with isobutene,* or t-butyl acetate3 and by conversion of the a- chloro-t-butyl esters to the amino esters via the azide, 4 a process which yields racemic esters. Some amino esters have been prepared from the free amino acids by reaction with ...
