(2S,4R)-1-(tert-Butoxycarbonyl)-4-fluoro-2-hydroxyMethylpyrrolidine

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

Procedure: The title compound was prepared as described in Example 53A substituting (2S,4R)-1-(tert-butoxycarbonyl)-4-fluoropyrrolidine-2-carboxylic acid for (2S,4S)-1-(tert-butoxycarbonyl)-4-fluoropyrrolidine-2-carboxylic acid. MS (DCI/NH3) m/z 220 (M+H)+.

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (2S,4R)-4-Fluoro-2-hydroxymethyl-pyrrolidine-1-carboxylic acid tert-butyl ester (2.87 g, 13.1 mmol) was dissolved in 45 mL of CH2Cl2. The mixture was cooled down to 0° C., and methanesulfonyl chloride (2.55 mL, 32.8 mmol) and triethylamine (4.56 mL, 32.8 mmol) were added. The mixture was allowed to warm to RT and stirred for 1.5 h. The mixture was quenched with a saturated aqueous solution of NaHCO3, extracted twice with CH2Cl2, dried over Na2SO4 and concentrated. The crude residue was purified by flash column chromatography on silica gel (c-hexane to c-hexane/EtOAC 3:7) to afford the desired material. TLC, Rf (c-hexane/EtOAc 1:1)=0.4; MS: 320.0 [M+Na]+, 198.1 [MH−Boc]+, 617.2 [2M+Na]+. to warm to RT The mixture was quenched with a saturated aqueous solution of NaHCO3 extracted twice with CH2Cl2 dried over Na2SO4 concentrated The crude residue was purified by flash column chromatography on silica gel (c-hexane to c-hexane/EtOAC 3:7)