tert-butyl (2S)-2-(2-oxoethyl)pyrrolidine-1-carboxylate

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1-BOC-2-(S)-pyrrolidineethanal (6.80 g, 26.5 mmol) in anhydrous toluene (100 mL), cooled to -78° C. was added a 1M solution of diisobutylaluminum hydride in toluene (132.5 mL, 132.5 mmol). The reaction was stirred at -78° C. for 2 hours, and diisobutylaluminum hydride solution (26.50 mL, 26.5 mmol) was added. The mixture was stirred for 2 hours, then the reaction was quenched at -78° C. with methanol (150 mL). The mixture was poured into 1M Rochelle salt (500 mL), and the emulsified solution was extracted with ethyl acetate (200 mL). The organic layer was washed with brine, dried over MgSO4, and concentrated. The residue was purified on silica gel, eluting with methanol/methylene chloride (5:95) to yield a colorless oil (3.82 g, 67%). MS (DCI/NM) m/e: 216 (M+H)+. 1HNMR (CDCl3, 300 MHz) δ: 1.47 (s, 9H), 1.58-1.76 (m, 2H), 1.82-2.05 (m, 3H), 3.31 (t, J=6.0 Hz, 2H), 3.50-3.69 (m, 2H), 4.10-4.21 (m, 1H), 4.43 (dd, J=4.0, 7.0 Hz, 1H). The mixture was stirred for 2 hours the reaction was quenched at -78° C. with methanol (150 mL) The mixture was poured into 1M Rochelle salt (500 mL) the emulsified solution was extracted with ethyl acetate (200 mL) The organic layer was washed with brine dried over MgSO4 concentrated The residue was purified on silica gel eluting with methanol/methylene chloride (5:95)