Réaction #1552097

Équation de réaction

benzene

(R)-(−)-2,2 dimethyl-1,3-dioxolane-4-methanol

potassium hydroxide

hexadecyl bromide

→

1-hexadecyl-glycerol

Rendement 79.0%

Solvants

water

Conditions de réaction

Traitement

1. 1
   Températurerefluxed for 6 hours
2. 2
   Autrewhile removing the water
3. 3
   Autreformed by azeotropic distillation
4. 4
   workup.STIRRINGstirred at this temperature overnight
5. 5
   Extractionthe obtained mixture was extracted thrice with 150 ml diethyl ether
6. 6
   LavageThe combined organic phase was washed with 150 ml water
7. 7
   Autrethe solvent was then removed under reduced pressure
8. 8
   workup.DISSOLUTIONThe residue was dissolved in 200 ml of a mixture of 90:10:5 (volume/volume) methanol
9. 9
   Températurewater:concentrated HCl, and the resulting solution was refluxed for 2 hours
10. 10
    TempératureAfter cooling to room temperature
11. 11
    workup.ADDITIONadding 200 ml water
12. 12
    Extractionthe product was extracted with 250 ml chloroform
13. 13
    LavageThe organic phase was washed consecutively with 250 ml water, 200 ml saturated aqueous solution of sodium carbonate
14. 14
    AutreThe solvent was removed under reduced pressure
15. 15
    Autrethe product was then crystallized from hexane (500 ml)

Mode opératoire

A mixture of 40 ml (R)-(−)-2,2 dimethyl-1,3-dioxolane-4-methanol, 55 grams of powdered potassium hydroxide and 109 ml hexadecyl bromide were added to 500 ml benzene, and the reaction mixture was stirred and refluxed for 6 hours, while removing the water formed by azeotropic distillation. The volume of the solvent was gradually reduced to about 150 ml. The reaction mixture was then cooled to room temperature and stirred at this temperature overnight. Thereafter, 150 ml water was added, and the obtained mixture was extracted thrice with 150 ml diethyl ether. The combined organic phase was washed with 150 ml water and the solvent was then removed under reduced pressure. The residue was dissolved in 200 ml of a mixture of 90:10:5 (volume/volume) methanol:water:concentrated HCl, and the resulting solution was refluxed for 2 hours. After cooling to room temperature and adding 200 ml water, the product was extracted with 250 ml chloroform. The organic phase was washed consecutively with 250 ml water, 200 ml saturated aqueous solution of sodium carbonate, and again with 200 ml water. The solvent was removed under reduced pressure and the product was then crystallized from hexane (500 ml) to give 81.25 grams (yield 79%) of pure 1-hexadecyl-glycerol, which was dried in a desiccator under reduced pressure.

Source