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% rhodium on carbon (10 mg). Hydrogen gas (ambient pressure) is applied to the mixture. The mixture is stirred at ambient temperature and pressure for 50 h. The mixture is then filtered over Celite® 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 21:79 (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