反应详情

A solution of 0.73 g of diethyl azodicarboxylate in 2 ml of tetrahydrofuran was added dropwise, whilst ice-cooling, to a solution of 2.1 g of (2R,4R)-4-hydroxy-2-{4-[2-(4-nitrobenzyloxycarbonyl)oxyethyl]-1-piperazinylcarbonyl}-1-(4-nitrobenzyloxycarbonyl)pyrrolidine [prepared as described in step (i) above] and 1.1 g of triphenylphosphine in 14 ml of tetrahydrofuran, and the resulting mixture was stirred at the same temperature for 10 minutes. A solution of 0.32 g of mercaptoacetic acid in 2 ml of tetrahydrofuran was then added dropwise to the mixture, and the mixture was stirred at room temperature for 1 hour. At the end of this time, the solvent was removed by distillation under reduced pressure, and the resulting residue was purified by column chromatography through silica gel, using a 20:1 by volume mixture of ethyl acetate and methanol as the eluent, to give 1.2 g of (2R,4S)-4-acetylthio-2-{4-[2-(4-nitrobenzyloxycarbonyl)oxyethyl]-1-piperazinylcarbonyl}-1-(4-nitrobenzyloxycarbonyl)pyrrolidine as a colorless powder.

1. stirringthe mixture was stirred at room temperature for 1 hour
2. customAt the end of this time, the solvent was removed by distillation under reduced pressure
3. customthe resulting residue was purified by column chromatography through silica gel
4. additionby volume mixture of ethyl acetate and methanol as the eluent