(S)-2-[(Azepane-1-carbonyl)-amino]-4-methyl-pentanoic acid 、
2-amino-2-methyl-3-(4-benzyloxy-phenyl)-propionic acid tert-butyl ester 在
silica gel 、 ethyl acetate heptane 作用下,
以to give a high Rf product as a white solid (0.43 g, 38%), mp=46-49° C.的产率得到2(R)-{2(S)-[(Azepane-1-carbonyl)-amino]-4-methyl-pentanoylamino}-3-(4-benzyloxy-phenyl)-2-methyl-propionic acid tert-butyl ester