反応 #55581

反応方程式

water

Cyclododecanone

(4-carboxybutyl) triphenylphosphonium bromide

sodium

→

5-cyclododecylidenepentanoic acid

収率 37.5%

溶媒

dimethylsulfoxide

dimethylsulfoxide

dimethylsulfoxide

反応条件

後処理

1. 1
   温度cooled in an ice-water bath
2. 2
   workup.ADDITIONadded to the above mixture
3. 3
   workup.STIRRINGthe mixture was stirred for 15 hr at room temperature
4. 4
   抽出This aqueous mixture was extracted with 900 ml (3×300 ml) of ether-ethyl acetate (1:1 V/V)
5. 5
   抽出The aqueous phase was then extracted with 900 ml (3×300 ml) of ether-hexane (1:1 V/V)
6. 6
   抽出The ether-hexane extract
7. 7
   乾燥was then dried over anhydrous magnesium sulfate
8. 8
   ろ過filtered
9. 9
   その他the solvent removed in vacuo
10. 10
    その他The resultant product was recrystallized from ethanol-water

実験手順

Dry dimethylsulfoxide (50 ml, distilled from calcium hydride) and 24.1 ml (0.06 mole) of the sodium salt of dimethylsulfoxide (2.49 M in dimethylsulfoxide, Fieser and Fieser, "Reagents for Organic Synthesis", 1:310 [1967]) were mixed together and cooled in an ice-water bath. Then 13.29 g (0.03 mole) of (4-carboxybutyl) triphenylphosphonium bromide (Aldrich Chemical Co.) was added thereto and the mixture was stirred for 30 min. Cyclododecanone (3.64 g, 0.02 mole; Aldrich Chemical Co.: Beilstein 7[2],36) was dissolved in 10 ml of dry dimethylsulfoxide and added to the above mixture and the mixture was stirred for 15 hr at room temperature. The resulting mixture was then poured into 500 ml of water. This aqueous mixture was extracted with 900 ml (3×300 ml) of ether-ethyl acetate (1:1 V/V). The aqueous phase was acidified (pH 1 to 2) with 30 ml of concentrated hydrochloric acid. The aqueous phase was then extracted with 900 ml (3×300 ml) of ether-hexane (1:1 V/V). The ether-hexane extract was then dried over anhydrous magnesium sulfate, filtered, and the solvent removed in vacuo. The resultant product was recrystallized from ethanol-water to yield 2.0 g (36.2%) of 5-cyclododecylidenepentanoic acid (mp 70°-72° C.) having the following physical characteristics:

出典