Imidazole → Methyl (2S,3S)-1-Boc-3-[(tert-butyldimethylsilyl)oxy]pyrrolidine-2-carboxylate

Participants

Reaction Steps

To a solution of (2S,3S)-N-tert-butyloxycarbonyl-3-hydroxy-2 pyrrolidinecarboxylic acid methyl ester (1B) (4.90 g, 20.0 mmol) in DMF (20 mL) at rt was added imidazole (3.41 g, 50.1 mmol), and then tert-butydimethylsilyl chloride (3.91 g, 25.9 mmol). After stirring at rt overnight, the reaction mixture was partitioned between H2O and CH2Cl2. The CH2Cl2 layer was washed with 1 M H3PO4, saturated aqueous NaHCO3 and brine, dried (MgSO4), then filtered and concentrated under reduced pressure. The residue was chromatographed (silica gel) eluting with 0-20% EtOAc/hexane to yield (2S,3S)-3-(tert-butyldimethylsilanyloxy)pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (6.86 g).

Provenance & Evidence