Ozone → (4R)-4-Benzyloxymethyl-4-(2-hydroxyethyl)-1-[(1R)-1-phenylethyl]pyrrolidin-2-one

Participants

Reaction Steps

A solution of (4R)-4-allyl-4-benzyloxymethyl-1-[(1R)-1-phenylethyl]pyrrolidin-2-one (4.00 g, 11.45 mmol) in dichloromethane (100 mL) was bubbled with ozone gas at −70° C. and stirred at the same temperature for 15 minutes. Ozone bubbling was stopped when the reaction solution was turned dark blue, and then the reaction solution was bubbled with nitrogen gas until the solution turned colorless. Sodium borohydride (434 mg, 11.45 mmol) and methanol (40 mL) were added at the same temperature, and the mixture was heated to room temperature over three hours. Sodium borohydride (325 mg, 8.58 mmol) was added, and the mixture was stirred at room temperature for further 24 hours. A saturated ammonium chloride solution was added, and the mixture was stirred for 10 minutes. Then, the reaction solution was poured into a mixture of ethyl acetate (200 mL) and water (200 mL), followed by extraction with ethyl acetate (500 mL). The organic layer was washed with brine (200 mL), and then dried over anhydrous sodium sulfate and filtered. The filtrate was then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=1:2→1:9→0:1) to give 3.22 g (79%) of the title compound as a colorless viscous oil.

Provenance & Evidence