Hydrochloric Acid → (3R,4R)-1-Benzylpyrrolidine-3,4-diol

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Reaction Conditions

Reaction Steps

Boron trifluoride ethyl etherate (36 ml, 0.29 mol) in diglyme (150 ml) was cooled to 0+ C. (3S,4S)-1-Benzyl-3,4-dihydroxy-2,5-dioxopyrrolidine (16 g, 72 mmol) and sodium borohydride were added slowly. The mixture was stirred at 70° C. for 2 hours. 6 N hydrochloric acid (100 ml) was added slowly and the mixture was heated at 70° C. for 15 minutes. Sodium fluoride (44.5 g, 1 mol) was added and the mixture was heated at reflux temperature for 1/2 hour. The mixture was cooled to room temperature. 20% Aqueous sodium hydroxide (85 ml) was added and the resulting mixture was filtered. The organic phase was isolated and evaporated to dryness. The residue was partitioned between water and diethyl ether. The water phase was extracted with ether (4×500 ml). The collected organic phases were dried over magnesium sulphate and evaporated to dryness. Recrystallization from ethyl acetate (25 ml) gave (3R,4R)-1-benzyl-3,4-pyrrolidinediol (12.3 g, yield: 88%) as white crystals.

Provenance & Evidence