反应详情

To a solution of cholic acid methyl ester (25 g, 59.2 mmol) in pyridine (75 mL), stirring at 0° C., was added methanesulfonyl chloride (5.04 mL, 65.1 mmol) dropwise over 30 minutes. The reaction was allowed to warm to room temperature and stir for 6 hours. The reaction mixture was poured into a mixture of EtOAc (200 mL), 1 N HCI (200 mL), and ice. The layers were separated, and the organic layer was washed with 1N HCI (2×50 mL), dried (Na2SO4) and concentrated to provide a light yellow oil. The crude material was passed through a plug of silica eluting with 50% EtOAc/hexanes to provide 24.5 g (83%) of the title compound as a light yellow oil that foamed into a white, sticky foam when placed on the high vacuum pump.

1. customThe layers were separated
2. washthe organic layer was washed with 1N HCI (2×50 mL)
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated
5. customto provide a light yellow oil