反应详情

To a stirring suspension of the product of Preparation 2, Step B, 5,6-O-isopropylidene-L-gulono-1,4-lactone (15.16 g, 69.5 mmol) in water (0.3 L) was added solid sodium periodate in small portions at 3° C. to 5° C. The pH of the mixture was adjusted to 5.5 with 1N aqueous sodium hydroxide. The suspension was stirred for 2 hours at ambient temperature, then saturated with sodium chloride (20.0 g) and filtered. To the filtrate, at 3° C. to 5° C., was added sodium borohydride (10.5 g, 0.278 mol) in small portions. The reaction mixture was stirred for 18 hours at ambient temperature. Acetone (100 mL) was added to destroy the excess of sodium borohydride, and the stirring was continued for 30 minutes. The acetone was removed under reduced pressure, and the aqueous residue was extracted with dichloromethane (3×300 mL) and EtOAc (3×300 mL). The combined organic layers were dried over magnesium sulfate, filtered, and evaporated to give (R)-(+)-(2,2-dimethyl-[1,3]dioxolan-4-yl)-methanol (5.07 g, 55.7%) as a colorless clear liquid: MS (APCI+)=132.9 (M++1).

1. filtrationsaturated with sodium chloride (20.0 g) and filtered
2. stirringThe reaction mixture was stirred for 18 hours at ambient temperature
3. customto destroy the excess of sodium borohydride
4. waitthe stirring was continued for 30 minutes
5. customThe acetone was removed under reduced pressure
6. extractionthe aqueous residue was extracted with dichloromethane (3×300 mL) and EtOAc (3×300 mL)
7. dry with materialThe combined organic layers were dried over magnesium sulfate
8. filtrationfiltered
9. customevaporated