反应详情

温度

-78 °C

A −78° C. solution of Example 26A (5.0 g, 18.9 mmol) in THF was treated with LDA (2M in hexanes, 11.5 mL, 22.6 mmol), stirred for 1 hour at −78° C., treated with methyl formate (2.34 mL, 37.8 mmol), stirred at −78° C. for 30 minutes, warmed to 0° C. for 1 hour, quenched with saturated NH4Cl and extracted three times with ethyl acetate. The combined extracts were washed with brine, dried (MgSO4), filtered, and concentrated. The residue was immediately dissolved in ethanol (100 mL), cooled to 0° C., and treated portionwise with NaBH4 (1.08 g). The reaction was stirred at 0° C. for 2 hours, quenched with acetone, stirred for 5 minutes, poured into water, and extracted three times with ethyl acetate. The combined extracts were washed with brine, dried (MgSO4), filtered, and concentrated. The residue was purified by flash column chromatography on silica gel with 2:1 hexanes/ethyl acetate to give 1.02 g of the desired product. Rf=0.84 (ethyl acetate).

1. stirringstirred at −78° C. for 30 minutes
2. temperaturewarmed to 0° C. for 1 hour
3. customquenched with saturated NH4Cl
4. extractionextracted three times with ethyl acetate
5. washThe combined extracts were washed with brine
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated
9. dissolutionThe residue was immediately dissolved in ethanol (100 mL)
10. temperaturecooled to 0° C.
11. additiontreated portionwise with NaBH4 (1.08 g)
12. stirringThe reaction was stirred at 0° C. for 2 hours
13. customquenched with acetone
14. stirringstirred for 5 minutes
15. additionpoured into water
16. extractionextracted three times with ethyl acetate
17. washThe combined extracts were washed with brine
18. dry with materialdried (MgSO4)
19. filtrationfiltered
20. concentrationconcentrated
21. customThe residue was purified by flash column chromatography on silica gel with 2:1 hexanes/ethyl acetate