1 2ZF N-(tert-butoxycarbonyl)-L-alpha-glutamyl-N-[(1r)-1-(carboxycarbonyl)-3,3-difluoropropyl]-L-leucinamide 1.000 2 0F7 N-[(benzyloxy)carbonyl]-L-isoleucyl-N-[(1r)-1-(carboxycarbonyl)-3,3-difluoropropyl]-L-leucinamide 0.714