Anisole → (3R,4R)-4-Methyl-5-oxopyrrolidine-3-carboxylic Acid

Participants

Reaction Conditions

Reaction Steps

To a crude product of (3R,4R)-1-(2,4-dimethoxybenzyl)-4-methyl-5-oxopyrrolidine-3-carboxylic acid (8.11 g) were added anisole (3.76 ml) and trifluoroacetic acid (40 ml), and the mixture was stirred at 80° C. for 5 hours. This reaction solution was cooled to room temperature, and concentrated under reduced pressure. To the resulting residue was added diisopropyl ether, and the mixture was stirred. The insoluble substance was collected by filtration, and dried under reduced pressure to give a crude product of the titled compound (2.23 g). To the resulting solid was added ethanol (8 ml), and the mixture was heated at reflux to dissolve, and then the solution was stirred at room temperature. A solid precipitated from the mixed solution was collected by filtration, washed with a small amount of cooled ethanol, and dried under reduced pressure to give the titled compound (1.36 g).

Provenance & Evidence