反应详情

0.65 g (3.69 mmol) of epoxide 2l (a mixture of 2l, 2l', 2l" above) in solution in 3 cm3 of anhydrous DMF were heated to reflux for 3 h; 91% of transposition ketone 6b was then detected by macrobore GC (verification by mass/GC coupling). 0.86 g (2 eq.) of DMAP were then added and the mixture was again heated to reflux for 3 h. It was acidified (pH=1) with 3N HCl, extracted with ether, concentrated, and a 3N sodium hydroxide solution was added to the ether phase (while the mixture was kept stirred for 5 to 10 min), the ether phase was removed and the material was washed once with ether. The aqueous phase was acidified using a solution with 3N HCl (pH=1) and was extracted with ether (4×15 cm3), dried over MgSO4, filtered and evaporated down. The crude product obtained was purified by flash chromatography on silica (eluent: ether/petroleum ether=5/95). 0.10 g of phenol 4h were obtained (macrobore GC purity>97%). The yield of compound 4h was 22%.

1. temperaturewere heated
2. temperatureto reflux for 3 h
3. temperaturethe mixture was again heated
4. temperatureto reflux for 3 h
5. extractionextracted with ether
6. concentrationconcentrated
7. additiona 3N sodium hydroxide solution was added to the ether phase (while the mixture
8. customwas removed
9. washthe material was washed once with ether
10. extractionwas extracted with ether (4×15 cm3)
11. dry with materialdried over MgSO4
12. filtrationfiltered
13. customevaporated down
14. customThe crude product obtained
15. customwas purified by flash chromatography on silica (eluent: ether/petroleum ether=5/95)