[(3aS,4R,6aR)-2,3,3a,4,5,6a-hexahydrofuro[2,3-b]furan-4-yl] (4-nitrophenyl) carbonate;benzyl 4-[[[(2R,3S)-3-[[(3aS,4R,6aR)-2,3,3a,4,5,6a-hexahydrofuro[2,3-b]furan-4-yl]oxycarbonylamino]-2-hydroxy-4-(4-phenylmethoxyphenyl)butyl]-(4-methoxyphenyl)sulfonylamino]methyl]piperidine-1-carboxylate;benzyl 4-[[[(2R,3S)-3-amino-2-hydroxy-4-(4-phenylmethoxyphenyl)butyl]-(4-methoxyphenyl)sulfonylamino]methyl]piperidine-1-carboxylate;benzyl 4-(aminomethyl)piperidine-1-carboxylate;benzyl 4-[[[(2R,3S)-2-hydroxy-3-[(2-methylpropan-2-yl)oxycarbonylamino]-4-(4-phenylmethoxyphenyl)butyl]-(4-methoxyphenyl)sulfonylamino]methyl]piperidine-1-carboxylate;tert-butyl N-[(1S)-1-[(2S)-oxiran-2-yl]-2-(4-phenylmethoxyphenyl)ethyl]carbamate;1-chlorylsulfanyl-4-methoxybenzene