反应详情

Cyclohexene (1.09 mL) was added to a 10 M dimethyl sulfide solution of borane (0.58 mL). Upon addition, a white solid had formed and 3 mL of degassed heptane was added to suspend it. The mixture was stirred for 5 minutes at room temperature. At this point, alkyne from Step 1 (15.5 g) in THF (55 mL) was added dropwise to the reaction mixture. After complete addition, the mixture was warmed to 40° C. for 20 minutes. Pinacolborane (8.48 mL) was added slowly to reaction mixture and the heating was continued for 2 hours at 40° C. The reaction mixture was cooled to room temperature and quenched with brine (100 mL). The mixture was extracted with ethyl acetate (3×). The combined organics were dried over magnesium sulfate, filtered and concentrated to provide the desired compound. 1H NMR (500 MHz, CDCl3): δ (ppm) 6.66-6.58 (m, 1H), 5.45 (d, 1H), 4.02-3.99 (m, 1H), 2.87 (s, 4H), 2.22-2.17 (m, 2H), 1.61-1.54 (m, 3H), 1.32-1.23 (m, 2H), 1.29 (s, 12H), 1.09-1.05 (m, 1H), 0.68-0.63 (m, 1H).

1. additionUpon addition
2. customa white solid had formed
3. additionAfter complete addition
4. temperaturethe mixture was warmed to 40° C. for 20 minutes
5. waitthe heating was continued for 2 hours at 40° C
6. temperatureThe reaction mixture was cooled to room temperature
7. customquenched with brine (100 mL)
8. extractionThe mixture was extracted with ethyl acetate (3×)
9. dry with materialThe combined organics were dried over magnesium sulfate
10. filtrationfiltered
11. concentrationconcentrated