1 PCM 1-[N[(phenylmethoxy)carbonyl]-L-leucyl-4-[[N/N-[(phenylmethoxy)carbonyl]-/nl-leucyl]amino]-3-pyrrolidinone/N 1.000 2 INP 4-[[N-[(phenylmethoxy)carbonyl]-/nl/N-leucyl]amino]-1[(2s)-2-[[[4-(pyridinylmethoxy)carbonyl]amino]-4-methylpent/nyl]-3-pyrrolidinone/N 0.932