تفاعل #5353

معادلة التفاعل

8-carbomethoxyoctanal

4-chlorobenzyltriphenylphosphonium chloride

water

potassium hexamethyldisilazide

→

10-(4-chlorophenyl)-dec-9-enoic acid methyl ester

المردود 13.0%

المذيبات

tetrahydrofuran

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONis added dropwise
2. 2
   درجة الحرارةto warm to room temperature
3. 3
   workup.STIRRINGstirred for 2 days
4. 4
   استخلاصextracting three times with diethyl ether
5. 5
   غسيلwashed with brine
6. 6
   تجفيفdried over Na2SO4
7. 7
   ترشيحfiltered
8. 8
   تركيزconcentrated in vacuo
9. 9
   أخرىto give a yellow solid
10. 10
    ترشيحPad filtration through flash silica gel eluting with 10% ethyl acetate/hexane
11. 11
    أخرىgives a yellow oil
12. 12
    تركيزafter concentration in vacuo
13. 13
    غسيلFlash chromatography on a 60 mm×150 mm silica column eluting with 5% ethyl acetate/hexane

الإجراء التجريبي

To a solution of 18.2 g (43 mmol) of 4-chlorobenzyltriphenylphosphonium chloride in 200 mL of dry tetrahydrofuran at -78° C. is added dropwise, 30.7 mL (43 mmol) of a 1.4M solution of potassium hexamethyldisilazide in tetrahydrofuran. This is allowed to stir for 1 hour when 8.0 g (43 mmol) of 8-carbomethoxyoctanal is added dropwise. The solution is stirred at -78° C. for 2 hours, allowed to warm to room temperature, and stirred for 2 days. The reaction is worked up by adding water and extracting three times with diethyl ether. The ether extracts are combined, washed with brine, dried over Na2SO4, filtered, and concentrated in vacuo to give a yellow solid. Pad filtration through flash silica gel eluting with 10% ethyl acetate/hexane, gives a yellow oil after concentration in vacuo. Flash chromatography on a 60 mm×150 mm silica column eluting with 5% ethyl acetate/hexane gives 1.62 g (13%) of 10-(4-chlorophenyl)-dec-9-enoic acid methyl ester as a mixture of E and Z isomers.

المصدر