反应详情

To a stirred and cooled (−78° C.) solution of the dibromofuran 10 (2.0 g, 7.9 mmol) in THF (20 mL) was added 1.6 M n-BuLi in hexane (10.2 mL, 16.3 mmol) over 3 min. After 1 h the cooling bath bath was removed and the mixture allowed to warm to r.t. Following a further 1.5 h the mixture was cooled back to −78° C. and then TMSCl (3.0 mL, 23.8 mmol) was added dropwise. The mixture was allowed to gradually warm up to r.t. After 19 h the mixture was poured into ice-cold Et2O-saturated aqueous NaHCO3 solution. The organic layer was separated and the aqueous layer extracted with Et2O (2×). The combined organic solutions were dried (MgSO4), filtered and concentrated to afford the crude acetylene 11 (1.83 g) as a yellow oil. This material was used in the next step without purification. 1H NMR (400 MHz; CDCl3) inter alia δ 0.23 (s, 9H), 6.44 (m, 1H), 7.34(m, 1H) and 7.63 (m, 1H).

1. customAfter 1 h the cooling bath bath was removed
2. temperaturethe mixture was cooled back to −78° C.
3. temperatureto gradually warm up to r.t
4. additionAfter 19 h the mixture was poured into ice-cold Et2O-saturated aqueous NaHCO3 solution
5. customThe organic layer was separated
6. extractionthe aqueous layer extracted with Et2O (2×)
7. dry with materialThe combined organic solutions were dried (MgSO4)
8. filtrationfiltered
9. concentrationconcentrated