(2S,3S)-tert-Butyl 3-((tert-butyldimethylsilyl)oxy)-2-formylpyrrolidine-1-carboxylate → (2S,3S)-N-tert-Butyloxycarbonyl-3-(tert-butyldimethylsilanyloxy)-2-((1R)-1-hydroxyethyl)pyrrolidine

Participants

Reaction Conditions

Reaction Steps

To a solution of intermediate (2S,3S)—N-tert-Butyloxycarbonyl-3-(tert-butyldimethylsilanyloxy)-2-formylpyrrolidine (4.7 g, 14.26 mmol) in THF (70 mL) at −78° C. was added dropwise MeMgBr (3.0 M in THF, 23.8 mmol). The reaction was stirred at −78° C. for 3 h and TLC (20% EtOAc/hexane) showed complete reaction. The reaction was quenched by the addition of HOAc (5.0 mL) at −78° C., warmed to rt and diluted with EtOAc (20 mL). The organic layer was separated and the aqueous layer was extracted with EtOAc (2×30 mL). The combined organic layers were washed with saturated NaHCO3 solution and brine, dried (MgSO4), filtered and concentrated to give the crude product. Purification by flash chromatography (120 g ISCO silica gel column, 0-30% EtOAc/hexane) provided 80A-a (760 mg) and 80A-b (1.54 g) as colorless oil. 80A-a: For (20% EtOAc/hexane) 0.29. 80A-b: For (20% EtOAc/hexane) 0.25.

Provenance & Evidence