Hydrochloric Acid → 1-Pyrrolidinecarboxylic acid, 4-(acetylthio)-2-(hydroxymethyl)-, 1,1-dimethylethyl ester, (2S,4S)-

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Reaction Steps

A solution of (2R,4S)-1-t-butoxycarbonyl-4-methanesulfonyloxypyrrolidine-2-methanol (i.e., a substrate) (11.8 g: 40 mmole) and potassium thioacetate (5.94 g: 52 mmole) in dimethylformamide (120 ml) is stirred at 65° C. for 3.75 hours. The reaction mixture is mixed with ethyl acetate (330 ml), ice water (100 ml), and 1N-hydrochloric acid (20 ml) to adjust the aqueous layer at pH 4. The organic layer is taken, successively washed with water and saturated brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue is purified by silica gel chromatography (toluene-ethyl acetate=2:1) to give (2S,4S)-4-acetylthio-1-t-butoxycarbonylpyrrolidine-2-methanol (9.48 g). Yield: 86%. Pale orange colored oil. NMR δ(CDCl3) ppm: 1.47(s, 9H), 2.34(s, 3H), 2.4 to 3.2(m, 2H), 3.58 to 4.1(m, 6H). IR ν (CHCl3) cm-1 : 3380, 1690.

Provenance & Evidence