반응 #2006465

반응 방정식

702

4-Carbethoxy-1,6-heptadiene

2,6-dibromophenol

→

703

수율 71.1%

(±)-3-Cyclopentenecarboxylic Acid, Ethyl Ester

수율 71.1%

용매

toluene

toluene

반응 조건

후처리

1. 1
   온도The resulting suspension was heated
2. 2
   온도at reflux under nitrogen for 1 h
3. 3
   기타the solvent was evaporated in vacuo
4. 4
   기타dried in vacuo for 30 min
5. 5
   온도After being cooled to r.t.
6. 6
   여과the mixture was filtered through a celite
7. 7
   세척the celite was rinsed with t-BuOMe
8. 8
   세척The combined filtrates were washed with 1% NaOH soln
9. 9
   농축water, and brine, and concentrated by evaporation at reduced pressure
10. 10
    workup.DISTILLATIONThe residue was distilled (37-38° C./1 Torr)

실험 절차

A flame-dried 500 mL flask was charged with 2,6-dibromophenol (1.20 g, 4.76 mmol), tungsten oxychloride (0.813 g, 2.38 mmol), and anhydrous toluene (25 mL). The resulting suspension was heated at reflux under nitrogen for 1 h, and then the solvent was evaporated in vacuo. The solid residue was broken up with a spatula and dried in vacuo for 30 min. To the residue were added toluene (160 mL), Et4Pb (1.54 g, 4.76 mL), and 702 (22 g, 131.0 mmol). The mixture was heated at 90° C. under nitrogen for 1.5 h. After being cooled to r.t., the mixture was filtered through a celite, and the celite was rinsed with t-BuOMe. The combined filtrates were washed with 1% NaOH soln, water, and brine, and concentrated by evaporation at reduced pressure. The residue was distilled (37-38° C./1 Torr) to give 13.06 g (71%) of 703 as a colorless liquid. 1H NMR (400 MHz, CDCl3) δ 5.67 (s, 2H, CH═CH), 4.14 (q, 2H, J=7.2 Hz, OCH2), 3.11 (pentuplet, J=7.6 Hz, 1H, CH), 2.65 (d, J=7.6 Hz, 4H, 2CH2), 1.27 (t, J=7.2 Hz, 3H, CH3).

출처