(1S,3aR,6aS)-4,4-Difluoro-octahydro-cyclopenta[c]pyrrole-1-carboxylic acid ethyl ester 、 L-OTBDMS-valine-L-valine-OH 在
N-羟基-7-氮杂苯并三氮唑 、
N,N'-二环己基碳二亚胺 作用下,
以66%的产率得到(1S,3aR,6aS)-2-{(S)-2-[(S)-2-(tert-Butyl-dimethyl-silanyloxy)-3-methyl-butyrylamino]-3-methyl-butyryl}-4,4-difluoro-octahydro-cyclopenta[c]pyrrole-1-carboxylic acid ethyl ester