反应详情

A solution of lithium bis(trimethylsilyl)amide (55 ml, 55 mmol, 1M in THF) was added to a mixture methoxy methyl triphenyl phosphonium chloride (18.9 g, 55 mmol) in 65 ml THF dropwise at 0° C. and stirred for 15 min. It was added to a mixture of the product of STEP 3 (7.3 g, 34.7 mmol) in 35 ml THF dropwise at 0° C. After 5 min, the reaction was quenched with H2O. The product was extracted with ethyl acetate. The aqueous layer was extracted with ethyl acetate. The combined organic layer was washed with H2O, brine, dried with Na0.2SO4, and concentrated. The residue was purified by chromatography (on silica gel, ethyl acetate/hexane=5/95) to give a colorless liquid in 6.3 g. This product was dissolved in 100 ml THF and 100 ml 2N HCl solution and heated at reflux for 30 min. The reaction was concentrated. The product was extracted with ethyl acetate and washed H2O. The aqueous layer was extracted with ethyl acetate. The combined organic layer was washed with brine, dried with Na2SO4, and concentrated. The residue was purified by chromatography (on silica gel, ethyl acetate/hexane=15/85) to yield a colorless oil in 3.8 g. NMR spectra of the product were consistent for the proposed structure.

1. waitAfter 5 min
2. customthe reaction was quenched with H2O
3. extractionThe product was extracted with ethyl acetate
4. extractionThe aqueous layer was extracted with ethyl acetate
5. washThe combined organic layer was washed with H2O, brine
6. customdried with Na0.2SO4
7. concentrationconcentrated
8. customThe residue was purified by chromatography (on silica gel, ethyl acetate/hexane=5/95)
9. customto give a colorless liquid in 6.3 g
10. temperatureat reflux for 30 min
11. concentrationThe reaction was concentrated
12. extractionThe product was extracted with ethyl acetate
13. washwashed H2O
14. extractionThe aqueous layer was extracted with ethyl acetate
15. washThe combined organic layer was washed with brine
16. dry with materialdried with Na2SO4
17. concentrationconcentrated
18. customThe residue was purified by chromatography (on silica gel, ethyl acetate/hexane=15/85)
19. customto yield a colorless oil in 3.8 g