反応 #2006465

反応方程式

702

4-Carbethoxy-1,6-heptadiene

2,6-dibromophenol

→

703

収率 71.1%

(±)-3-Cyclopentenecarboxylic Acid, Ethyl Ester

収率 71.1%

溶媒

toluene

toluene

反応条件

後処理

1. 1
   温度The resulting suspension was heated
2. 2
   温度at reflux under nitrogen for 1 h
3. 3
   その他the solvent was evaporated in vacuo
4. 4
   その他dried in vacuo for 30 min
5. 5
   温度After being cooled to r.t.
6. 6
   ろ過the mixture was filtered through a celite
7. 7
   洗浄the celite was rinsed with t-BuOMe
8. 8
   洗浄The combined filtrates were washed with 1% NaOH soln
9. 9
   濃縮water, and brine, and concentrated by evaporation at reduced pressure
10. 10
    workup.DISTILLATIONThe residue was distilled (37-38° C./1 Torr)

実験手順

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).

出典