Formic Acid → (R)-4-((S)-1-hydroxyethyl)-1-((S)-1-(4-methoxyphenyl)ethyl)pyrrolidin-2-one

Participants

Reaction Conditions

Reaction Steps

2.4 g of Dichloro-(pentamethylcyclopentadienyl)-rhodium-(III)-dimer and 2.8 g (R,R)—N-(p-toluenesulfonyl)-1,2-diphenylethylendiamine [(R,R)-TsDPEN] is added to a solution of 50 g (R)-4-acetyl-1-[(S)-1-(4-methoxyphenyl)-ethyl]pyrrolidine-2-one in acetonitril at 25° C. The solution is cooled to −15° C. At this temperature a mixture of 22 mL formic acid and 135 mL triethylamine is added. The reaction mixture is stirred for 22 hours at −15° C. and then warmed up to 20° C. 230 mL of a 4 molar hydrochloric acid is added under cooling. The aqueous phase is extracted 3 times with ethyl acetate. The organic phase is washed with diluted and concentrated brine and treated with activated carbon. The organic phase is dried over sodium sulfate. The solvent is evaporated under reduced pressure to obtain 57.1 g of a beige solid with a diastereomeric purity of ˜97:3.

Provenance & Evidence