反应详情

At −78° C., BF3.etherate (0.6 mL, 4.8 mmol) was added to a solution containing 47 (1.7 g, 3.9 mmol) in anhydrous DCM (40 mL). After 10 min, DIBAL (1 M/DCM, 10 mL, 10 mmol) was added dropwise from an addition funnel. After 5 min following the complete addition of the DIBAL solution, EtOAc (10 mL) was added to quench the excess reagent. Dilute aqueous HCl was slowly added and the reaction mixture was allowed to slowly warm to ambient temperature. The product was extracted with DCM and EtOAc and the combined organic extracts were washed with dilute aqueous HCl, water, brine, dried over anhydrous Na2SO4, filtered and concentrated. The crude product was purified by flash silica gel chromatography (EtOAc/hexane, 1:2) to afford 1.1 g (72%) of 60 as a yellow-colored oil. 1H NMR (CDCl3, 300 MHz) δ7.65 & 7.03 (rotamer, d and app t, J=6.9, 7.8 Hz, 1H), 7.38 (m, 5H), 7.26-7.19 (m, 2H), 6.70-6.52 (m, 2H), 5.26-5.14 (m, 2H), 4.38 (m, 1H), 4.28 (m, 1H), 4.14 (m, 1H), 3.43 (m, 2H), 3.27 & 3.02 (rotamer, 2 m, 1H), 2.76-2.68 (m, 1H), 2.45 (m, 1H), 1.77-1.68 (m, 5H) ppm.

1. customAt −78° C.
2. additionetherate (0.6 mL, 4.8 mmol) was added to a solution
3. waitAfter 5 min following
4. additionwas added
5. customto quench the excess reagent
6. additionDilute aqueous HCl was slowly added
7. extractionThe product was extracted with DCM and EtOAc
8. washthe combined organic extracts were washed with dilute aqueous HCl, water, brine
9. dry with materialdried over anhydrous Na2SO4
10. filtrationfiltered
11. concentrationconcentrated
12. customThe crude product was purified by flash silica gel chromatography (EtOAc/hexane, 1:2)