ethyl (2S)-2-[[4-[(2S,3R)-2-[[(3aS,4R,6aR)-2,3,3a,4,5,6a-hexahydrofuro[2,3-b]furan-4-yl]oxycarbonylamino]-3-hydroxy-4-[[4-(4-methylpiperazin-1-yl)phenyl]sulfonyl-(2-methylpropyl)amino]butyl]phenoxy]methyl-phenoxyphosphoryl]oxypropanoate;ethyl (2S)-2-[[4-[(2S,3R)-2-[[(3aS,4R,6aR)-2,3,3a,4,5,6a-hexahydrofuro[2,3-b]furan-4-yl]oxycarbonylamino]-3-hydroxy-4-[2-methylpropyl-[4-(4-phenacylpiperazin-1-yl)phenyl]sulfonylamino]butyl]phenoxy]methyl-phenoxyphosphoryl]oxypropanoate;ethyl (2S)-2-[[4-[(2S,3R)-2-[[(3aS,4R,6aR)-2,3,3a,4,5,6a-hexahydrofuro[2,3-b]furan-4-yl]oxycarbonylamino]-3-hydroxy-4-[2-methylpropyl-[4-[4-(2,2,2-trifluoroacetyl)piperazin-1-yl]phenyl]sulfonylamino]butyl]phenoxy]methyl-phenoxyphosphoryl]oxypropanoate;4-piperidin-1-ylbenzenesulfonyl chloride