تفاعل #2006465

معادلة التفاعل

702

4-Carbethoxy-1,6-heptadiene

2,6-dibromophenol

→

703

المردود 71.1%

(±)-3-Cyclopentenecarboxylic Acid, Ethyl Ester

المردود 71.1%

المذيبات

toluene

toluene

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe resulting suspension was heated
2. 2
   درجة الحرارةat reflux under nitrogen for 1 h
3. 3
   أخرىthe solvent was evaporated in vacuo
4. 4
   أخرىdried in vacuo for 30 min
5. 5
   درجة الحرارةAfter being cooled to r.t.
6. 6
   ترشيحthe mixture was filtered through a celite
7. 7
   غسيلthe celite was rinsed with t-BuOMe
8. 8
   غسيلThe combined filtrates were washed with 1% NaOH soln
9. 9
   تركيزwater, and brine, and concentrated by evaporation at reduced pressure
10. 10
    workup.DISTILLATIONThe residue was distilled (37-38° C./1 Torr)

الإجراء التجريبي

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).

المصدر