Sulfuric Acid → (2S,4R)-1-allyloxycarbonyl-4-methanesulfonyloxypyrrolidine-2-methanol

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Reaction Steps

To a solution of (2S,4R)-1-allyloxycarbonyl-4-methanesulfonyloxy-2-methoxycarbonylpyrrolidine (27.12 g: 74.0 mmole) in a mixture of tetrahydrofuran (94 ml) and ethanol (140 ml), sodium borohydride (12 g: 31.7 mmole) is added in a nitrogen atmosphere under ice cooling. The mixture is stirred for 4 hours at room temperature. To the reaction mixture concentrated sulfuric acid (8.8 ml: 158.4 mmole) is added dropwise under ice cooling. The reaction mixture is concentrated to half a volume in vacuo, and diluted with ethyl acetate (100 ml) and ice water (100 ml). The organic layer is taken, successively washed with aqueous sodium hydrogen carbonate and saturated brine, dried over magnesium sulfate, and concentrated in vacuo to give (2S,4R)-1-allyloxycarbonyl-4-methanesulfonyloxypyrrolidine-2-methanol (19.33 g). Yield: 77%. Colorless oil. NMR δ(CDCl3) ppm: 1.9 to 2.1(m, 1H), 2.3 to 2.5(m, 1H), 3.05(s, 3H), 3.5 to 3.7(m, 2H), 3.7 to 4.1(m, 2H), 4.1 to 4.3(m, 1H), 4.6(m, 2H), 5.2 to 5.4(m, 3H), 5.8 to 6.1(m, 1H).

Provenance & Evidence