Iodine → (+/-)-(4R*,5R*)-5-[(1R*)-2-(3-chlorophenyl)-1-hydroxyethyl]-1-methyl-4-phenylpyrrolidin-2-one

Participants

Reaction Steps

A portion of a mixture of 3-chlorobenzyl bromide (0.53 mL, 4.0 mmol) and Et2O (0.5 mL) was added to Mg turnings and I2 (catalytic amount) in Et2O (4 mL). Once the reaction was initiated, the rest of the 3-chlorobenzyl bromide was added. When the reaction subsided, the resulting green mixture was transferred into a −78° C. suspension of CeCl3 (1.05 g, 4.3 mmol) in THF (4 mL). A solution of the (±)-(4R*,5R*)-5-formyl-1-methyl-4-phenylpyrrolidin-2-one (Intermediate Z, 1M in THF, 3 mL, 3 mmol) was added and the reaction mixture was allowed to warm to room temperature, then was treated with a saturated NH4Cl solution and extracted with EtOAc. The combined organic layers were washed with water and a saturated NaCl solution, dried (Na2SO4) and concentrated under reduced pressure. The crude green oil was purified by flash chromatography (EtOAc) to give (±)-(4R*,5R*)-5-[(1R*)-2-(3-chlorophenyl)-1-hydroxyethyl]-1-methyl-4-phenylpyrrolidin-2-one (340 mg, 34%): mp 50-52° C.; TLC (EtOAc) Rf 0.25.

Provenance & Evidence