반응 #50114

반응 방정식

epoxide

1-chloro-3,3-difluoro-2-methyl-7-oxabicyclo[4.1.0]heptane

2l

1-chloro-3,3-difluoro-2-methyl-7-oxabicyclo[4.1.0]heptane

2l

1-chloro-3,3-difluoro-2-methyl-7-oxabicyclo[4.1.0]heptane

2l

1-chloro-3,3-difluoro-2-methyl-7-oxabicyclo[4.1.0]heptane

HCl

→

phenol

수율 21.5%

3-fluoro-2-methylphenol

수율 21.5%

용매

DMF

반응 조건

후처리

1. 1
   온도were heated
2. 2
   온도to reflux for 3 h
3. 3
   온도the mixture was again heated
4. 4
   온도to reflux for 3 h
5. 5
   추출extracted with ether
6. 6
   농축concentrated
7. 7
   workup.ADDITIONa 3N sodium hydroxide solution was added to the ether phase (while the mixture
8. 8
   기타was removed
9. 9
   세척the material was washed once with ether
10. 10
    추출was extracted with ether (4×15 cm3)
11. 11
    건조dried over MgSO4
12. 12
    여과filtered
13. 13
    기타evaporated down
14. 14
    기타The crude product obtained
15. 15
    기타was purified by flash chromatography on silica (eluent: ether/petroleum ether=5/95)

실험 절차

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%.

출처