反应详情

温度

-65 °C

To a solution of (3R,4R,5R)-3,4-Bis(benzyloxy)-5-(benzyloxymethyl)-3-methyl-dihydrofuran-2(3H)-one (250 mmol) in toluene (625 mL) cooled to −70° C. was added dropwise a 1.5 M solution of Dibal in Toluene (250 mL, 375 mmol) at such a rate so that the reaction temperature does not go above −65° C. The reaction was further stirred at −65° C. for 15 mins (TLC analysis showed completion of reaction, 25% ethyl acetate in hexanes). The excess Dibal was destroyed by adding acetone (40 mL) to the reaction mixture while maintaining the temperature below −60° C. The reaction was diluted with cold 2.5 N HCl (300 mL), water (475 mL) and allowed to warm to 0° C. The reaction was extracted with ethyl acetate (625 mL). The organic layer was separated and washed with brine (500 mL), dried over MgSO4, filtered and the filtrate was concentrated in vacuum to dryness to furnish (3R,4R,5R)-3,4-bis(benzyloxy)-5-(benzyloxymethyl)-3-methyl-tetrahydrofuran-2-ol (112 g) as an oil, which was used in the next step without further purification.

1. customdoes not go above −65° C
2. customThe excess Dibal was destroyed
3. additionby adding acetone (40 mL) to the reaction mixture
4. temperaturewhile maintaining the temperature below −60° C
5. additionThe reaction was diluted with cold 2.5 N HCl (300 mL), water (475 mL)
6. temperatureto warm to 0° C
7. extractionThe reaction was extracted with ethyl acetate (625 mL)
8. customThe organic layer was separated
9. washwashed with brine (500 mL)
10. dry with materialdried over MgSO4
11. filtrationfiltered
12. concentrationthe filtrate was concentrated in vacuum to dryness