tert-Butyl-(2S,3R)-3-{[tert-butyl(dimethyl)silyl]oxy}-2-formylpyrrolidine-1-carboxylate → (2R,3R)-3-(tert-Butyl-dimethylsilanyloxy)-2-[(1S)-(1-hydroxy-2-methylpropyl)]pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To (2S,3R)-3-(tert-butyldimethylsilanyloxy)-2-formylpyrrolidine-1-carboxylic acid tert-butyl ester (7C) (6.50 g, 19.8 mmol) in THF (100 mL) at −78° C. was added a 2M THF solution of isopropylmagnesium chloride (30.0 mL, 60.0 mmol) over 20 min. The cold bath was removed and the reaction was stirred for 1 h. The reaction was then cooled to 60° C. and was quenched with saturated aqueous ammonium chloride. After warming to rt, the whole was diluted with EtOAc. The layers were separated and the organic layer washed with water and brine, then dried (MgSO4), filtered and concentrated. The resulting residue was purified via flash chromatography eluting with 20% EtOAc/hexane to provide (2R,3R)-3-(tert-butyldimethylsilanyloxy)-2-[(1S)-(1-hydroxy-2-methyl-propyl)]-pyrrolidine-1-carboxylic acid tert-butyl ester (10A) (5.90 g).

Provenance & Evidence