Sodium Acetate → N-(methoxycarbonyl)-4-keto-D-proline methyl ester

Participants

Reaction Conditions

Reaction Steps

A 200 mL aqueous solution containing 0.200M sodium acetate (pH 5.0), 1.3325 g of Candida antartica lipase fraction B, and 4.02 g of racemic N-(methoxycarbonyl)-4-keto-D,L-proline methyl ester (100 mM) was stirred at 25° C. After 24 h, an 96% enantiomeric excess of N-(methoxycarbonyl)-4-keto-D-proline methyl ester was obtained at 50% conversion of the racemic mixture. The reaction mixture was filtered using a 10,000 MWCO membrane filter (Amicon) to remove the enzyme catalyst, and the filtrate extracted with three 200 mL portions of dichloromethane. The combined organic extracts were dried over magnesium sulfate, filtered, and the dichloromethane removed from the filtrate by rotary evaporation at reduced pressure. Residual dichloromethane was removed from the resulting colorless oil at high vacuum (50 millitorr) to produce N-(methoxycarbonyl)-4-keto-D-proline methyl ester as a white solid (1.99 g, 99% isolated yield, 99% purity (by GC), 97% ee).

Provenance & Evidence