反应详情

To a stirring 20°-25° 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, 0.038 mol) in methylene chloride (250 mL) containing triethylamine (7 mL, 0.05 mol) is added 2-nitrobenzenesulfonyl chloride (9.8 g, 0.043 mol). Stirring is continued at 20°-25° C. for 24 hours, a further portion of 2-nitrobenzenesulfonyl chloride (2.0 g, 0.009 mol) is added and the solution stirred for a further 4 hours. The solution is then poured onto 200 mL of water and the layers separated. The upper aqueous layer is extracted with 250 mL of methylene chloride and the combined organic layers are washed with 100 mL each of saturated sodium bicarbonate solution to ensure complete removal of 2-nitrobenzenesulfonyl chloride and then saturated sodium chloride. Drying the solution with magnesium sulfate and concentration in vacuo gives 20.8 g of the product as a green oil.

1. stirringthe solution stirred for a further 4 hours
2. customthe layers separated
3. extractionThe upper aqueous layer is extracted with 250 mL of methylene chloride
4. washthe combined organic layers are washed with 100 mL each of saturated sodium bicarbonate solution
5. customremoval of 2-nitrobenzenesulfonyl chloride
6. customDrying the solution
7. concentrationwith magnesium sulfate and concentration in vacuo