An efficient synthesis of methyl N-[2-(R)-(1-napthylmethyl)-3-(morpholinocarbonyl)propionyl]-(S)-histidinate, the key synthetic intermediate of renin inhibitors
succinic acid over a rhodium (I)-chiral phosphine complex. Highly chemoselective amide formation of di-4-nitrophenyl (R)-(1-naphthylmethyl)succinate with morpholine followed by coupling with methyl (S)-histidinate readily produced the title key synthetic intermediate.