Solution-Phase Parallel Synthesis of Dissymmetric Disubstituted Malonamides Carrying Amino Ester Residues

Amino esters were used as nucleophiles in the reaction with Meldrum’s acid to obtain monosubstituted malonic acids that reacted under coupling reaction conditions with a second different amino ester residue to give single >COCH2CO< retropeptide units in high overall yields. The synthetic procedure led to the construction of a 4 × 5 combinatorial library of malonyl peptides.