3-(R)-Tert-butyldimethylsilyloxy-4-(S)-(1-ethoxycarbonylcyclopropyl)-1-[1-(S)-phenylethyl]-2-pyrrolidinethione → 3-(S)-Tert-butyldimethylsilyloxy-4-(R)-(1-ethoxycarbonylcyclopropyl)-1-[1-(S)-phenylethyl]pyrrolidine

Participants

Reaction Steps

3-(R)-Tert-butyldimethylsilyloxy-4-(S)-(1-ethoxycarbonylcyclopropyl)-1-[1-(S)-phenylethyl]-2-pyrrolidinethione (7.96 g, 17.74 mmol) was dissolved in anhydrous ethanol (490 ml), and the solution was mixed with Raney nickel (25 ml) and heated under reflux for 40 minutes. After removing the catalyst by celite filtration (ethanol washing), the resulting filtrate was concentrated under reduced pressure. The thus obtained residue was dissolved in chloroform (400 ml), washed with 10% ammonia water (300 ml), water (300 ml) and saturated brine (300 ml) in that order and then dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure and the resulting residue was subjected to flash silica gel chromatography and eluted with an eluant of n-hexane:ethyl acetate=6:1, to thereby obtain 5.48 g (74%) of the title compound as a colorless oil.

Provenance & Evidence