Isopropyl Acetate → (3R,5S)-5-biphenyl-4-ylmethyl-3-methyl-2-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

Isopropyl acetate (1 ml) is added to a mixture of 100 mg (R)-5-biphenyl-4-ylmethyl-3-methylene-2-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester (4-a, R1=Boc) and 10% platinum on carbon (10 mg). Hydrogen gas (ambient pressure) is applied to the mixture. The mixture is stirred at ambient temperature and pressure for 4 h. The mixture is then filtered over Celites and washed with isopropyl acetate (2×0.5 ml). The mixture is then concentrated in vacuo to give (3R,5S)-5-biphenyl-4-ylmethyl-3-methyl-2-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester (3-a, R1=Boc) and (3S,5S)-5-biphenyl-4-ylmethyl-3-methyl-2-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester (3-b, R1=Boc). Diastereomer ratio 33:67 (3-a, R1=Boc: 3-b, R1=Boc) as determined by hplc. Spectroscopic data in described in WO/2008/083967, for example, Examples 14 and 18.

Provenance & Evidence