Acetic Acid → tert-Butyl (2R,4R)-4-hydroxy-2-(hydroxymethyl)pyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

(2R,4R)-1-(tert-Butyloxycarbonyl)-2-carbomethoxy-4-hydroxypyrrolidine 36 (7.0 g, 28.6 mmol) was dissolved in dry THF (100 ml) and cooled in ice salt bath under argon atmosphere. To this cold solution was added lithium borohydride (1.88 g, 85.8 mmol) in small portions during 15 min period. After the addition of lithium borohydride, the reaction mixture was allowed to stir at 0° C. for 1 h followed by 15 h at room temperature under argon. The solution was cooled to 0° C. and diluted with water (50 ml) and the pH was adjusted with AcOH to 6. The reaction was evaporated to dryness and dissolved in EtOAc (200 ml), washed with water (100 ml) and brine (100 ml). The EtOAc extract was dried and evaporated to dryness. The residue was purified by flash column chromatography over silica gel using CH2Cl2 →EtOAc as the eluent. The pure fractions were collected and evaporated to dryness to afford 5.00 g (81%) of clear oil. The oil on standing gave colorless solid. mp: 95-97C. 1HNMR (CDCl3): 1.45 (s, 9H, Boc), 1.90 (dd, 1H), 2.34 (m, 1H), 3.40 -3.62 (m, 3H), 4.00 (m, 2H), 4.28 (bs, 1H), 4.44 (m, 1H).

Provenance & Evidence