反应详情

The ketal (2 g, 8.5 mmol) obtained from step A, Example 7 was dissolved in pyridine (40 mL) and the solution was cooled in an ice bath. To it was added SOCl2 (3.1 mL, 42.5 mmol). The solution was allowed to warm to room temperature and stirring was continued overnight. The reaction was quenched by addition of ice and then water. The resulting solution was extracted with EtOAc three times. The combined EtOAc layer was dried over MgSO4 and concentrated. Flash chromatography on silica gel eluting with 0 to 55% EtOAc/hexanes provided 1.54 g of the title compound. MS calculated (M+H)+ 218, found 218.

1. temperaturethe solution was cooled in an ice bath
2. customThe reaction was quenched by addition of ice
3. extractionThe resulting solution was extracted with EtOAc three times
4. dry with materialThe combined EtOAc layer was dried over MgSO4
5. concentrationconcentrated