methyl (2S)-2-[[(2S)-2-[[(2R)-2-amino-6-[(4-methylphenyl)sulfonylamino]hexanoyl]amino]-3-phenylpropanoyl]amino]-6-(phenylmethoxycarbonylamino)hexanoate 、
formic anhydride 生成
N-α-Formyl-N-ε-(p-tosyl)-D-lysyl-L-phenylalanyl-N-ε-benzyloxycarbonyl-L-lysine methyl ester