2-nitrobenzyl (2,6-bis(hydroxymethyl)phenyl)carbamate 、 [(19S)-7-carbonochloridoyloxy-19-ethyl-14,18-dioxo-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2(11),3,5,7,9,15(20)-heptaen-19-yl] carbonochloridate 在
4-二甲氨基吡啶 作用下,
以35 mg的产率得到[(19S)-19-ethyl-14,18-dioxo-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4,6,8,10,15(20)-heptaen-19-yl] [3-[[(19S)-19-ethyl-14,18-dioxo-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4,6,8,10,15(20)-heptaen-19-yl]oxycarbonyloxymethyl]-2-[(2-nitrophenyl)methoxycarbonylamino]phenyl]methyl carbonate