反应详情

A solution of 1.93 g (5.22 mmoles) of (3S, 5S)-5-[(1S)-1-(N-t-butoxycarbonylamino)-2-cyclohexylethyl]-3-(1-hydroxy-1-methylethyl)dihydrofuran-2(3H)-one (prepared as described in Preparation 6) in 50 ml of methanol was saturated with gaseous methylamine by passing the gas through the solution whilst ice-cooling, and then the flask containing the reaction mixture was stoppered tightly and allowed to stand at room temperature overnight. The reaction mixture was then concentrated by evaporation under reduced pressure, and the residue was purified by medium pressure silica gel column chromatography (using a 20:1 by volume mixture of methylene chloride and methanol as eluent), followed by recrystallization from hexane, to give 1.98 g (yield 95%) of the title compound as white crystals, melting at 174°-175° C.

1. temperaturecooling
2. additionthe flask containing the reaction mixture
3. concentrationThe reaction mixture was then concentrated by evaporation under reduced pressure
4. customthe residue was purified by medium pressure silica gel column chromatography (
5. additionby volume mixture of methylene chloride and methanol as eluent),
6. customfollowed by recrystallization from hexane