反应详情

To a stirring 0°-5° C. solution of the (4R-cis)-1,1-dimethylethyl 6-hydroxymethyl-2,2-dimethyl-1,3-dioxane-4-acetate (European Patent Application 0319,847) (10 g, 38 mmol) in methylene chloride (250 mL) containing triethylamine (10 mL, 72 mmol) is added 2,5-dichlorobenzenesulfonyl chloride (14.7 g, 57.5 mmol). Stirring is continued at 0°-5° C. for 3.5 hours, the solution is poured onto 200 mL of water, and the layers separated. The upper aqueous layer is extracted with 200 mL of methylene chloride and the combined organic layers are washed with 200 mL each of saturated sodium bicarbonate solution to ensure complete removal of 2,5-dichlorobenzenesulfonyl chloride and then saturated sodium chloride solution. Drying the solution with magnesium sulfate and concentration in vacuo gives 24.6 g of the product as a yellow-orange oil.

1. customthe layers separated
2. extractionThe upper aqueous layer is extracted with 200 mL of methylene chloride
3. washthe combined organic layers are washed with 200 mL each of saturated sodium bicarbonate solution
4. customremoval of 2,5-dichlorobenzenesulfonyl chloride
5. customDrying the solution
6. concentrationwith magnesium sulfate and concentration in vacuo