反应详情

Trifluoroacetic acid (20 ml) was added slowly to a mixture of anisole (5 ml) and diphenylmethyl (6R,7R)-3-carbamoyloxymethyl-7-[2-(fur-2-yl)-2-methoxyiminoacetamido]ceph-3-em-4-carboxylate (syn isomer) (4.7 g, 8 mmole) which had been cooled in an ice-bath. The flask was shaken occasionally during the next 10 minutes to ensure complete solution of the solid. It was then removed from the ice-bath and excess trifluoroacetic acid was removed on a rotary evaporator. Trituration of the residue with ethyl acetate (5 ml) gave (6R,7R)-3-carbamoyloxymethyl-7-[2-(fur-2-yl)-2-methoxyiminoacetamido]ceph-3-em-4-carboxylic acid (syn isomer) (3.3 g, 94%) as a solid which was filtered off and washed with diethyl ether.

1. temperaturehad been cooled in an ice-bath
2. customIt was then removed from the ice-bath and excess trifluoroacetic acid
3. customwas removed on a rotary evaporator