4-Toluenesulfonyl chloride → (2S,4R)-1-p-nitrobenzyloxycarbonyl-4-methanesulfonyloxypyrrolidine-2-methanol p-toluenesulfonate

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Reaction Conditions

Reaction Steps

To a solution of (2S,4R)-1-p-nitrobenzyloxycarbonyl-4-methanesulfonyloxypyrrolidine-2-methanol (28.8 g: 77 mmole) in dichloromethane (150 ml) under ice cooling, p-toluenesulfonyl chloride (19.11 g: 1.3 eq.), triethylamine (10.4 ml: 1.3 eq.) and dimethylaminopyridine (0.94 g: 0.1 eq.) are added. The mixture is stirred at 25° C. for 7 hours. The reaction mixture is diluted with ice water. The resultant organic layer is taken, successively washed with aqueous sodium hydrogen carbonate and water, dried over magnesium sulfate, and concentrated in vacuo. The residue is recrystallized from n-hexane to give (2S,4R)-1-p-nitrobenzyloxycarbonyl-4-methanesulfonyloxypyrrolidine-2-methanol p-toluenesulfonate (37.7 g). Yield: 93%. NMR δ(CDCl3) ppm: 2.20 to 2.50(m, 1H), 2.44(s, 3H), 3.05(s, 3H), 3.45 to 4.60(m, 5H), 5.18(s, 2H), 5.26(br s, 1H), 7.34(d, J=8 Hz, 2H), 7.50(d, J=8 Hz, 2H), 7.75(d, J=8 Hz, 2H), 8.23(d, J=8 Hz, 2H). IR ν (CHCl3) cm-1 : 1700, 1599.

Provenance & Evidence