反应详情

70% Perchloric acid (3.4 ml) was added to a solution of 7-(2-methoxyimino-3,3-diethoxy-4-bromobutyramido)-3-hydroxycepham-4-carboxylic acid (syn isomer, 5.0 g) in acetone (40 ml) under ice-cooling and stirred at the same temperature for an hour. The precipitates were collected by filtration, washed with acetone (5 ml) twice and dried to give 7-(2-methoxyimino-3-oxo-4-bromobutyramido)-3-hydroxycepham-4-carboxylic acid (syn isomer, 1.85 g).

1. temperaturecooling
2. filtrationThe precipitates were collected by filtration
3. washwashed with acetone (5 ml) twice
4. customdried