Ethyl Acetate → 1-Pyrrolidinecarboxylic acid, 4-(acetylthio)-2-(hydroxymethyl)-, 2-propen-1-yl ester, (2S,4S)-

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Reaction Conditions

Reaction Steps

A solution of (2S,4R)-1-allyloxycarbonyl-4-methanesulfonyloxypyrrolidine-2-methanol (19.32 g: 69.17 mmole) and 90% potassium thioacetate (10.73 g: 89.9 mmole) in dimethylformamide (217 ml) is heated with stirring at 65° C. for 5 hours. To the reaction mixture ethyl acetate (200 ml) and ice water (200 ml) are added. The organic layer is taken, successively washed with aqueous 0.05N-sodium hydroxide, 0.1N-hydrochloric acid, water and saturated brine, dried over magnesium sulfate, and concentrated in vacuo. The residue is purified by silica gel chromatography to give (2S,4S)-4-acetylthio-1-allyloxycarbonylpyrrolidine-2-methanol (15.34 g). Yield: 90%. NMR δ(CDCl3) ppm: 1.5 to 1.7(m, 1H), 2.34(s, 3H), 2.4 to 2.6(m, 1H), 3.19(dd, J=8.0 Hz, J=11.5 Hz, 1H), 3.6 to 3.8(m, 2H), 3.8 to 4.0(m, 1H), 4.0 to 4.2(m, 2H), 4.6(m, 2H), 5.2 to 5.4(m, 2H), 5.8 to 6.1(m, 1H).

Provenance & Evidence