Reacción #548441

Ecuación de reacción

4-hydroxy-2-(6-carboxyhexyl) cylopent-2-en-1-one

2-(6-carboxyhexyl)-4-hydroxy-cyclopent-2-en-1-one

sodium chloride

p-toluenesulfonic acid monohydrate

sodium bicarbonate

dihydropyran

→

4-tetrahydropyranyloxy-2-(6-tetrahydropyranylcarboxyhexyl)cylopent-2-en-1-one

Disolventes

water

ether

methylene chloride

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe temperature is maintained at 20°-25° C.
2. 2
   Temperaturaby cooling
3. 3
   workup.ADDITIONThe solution is diluted with 200 ml
4. 4
   OtroThe phases are separated
5. 5
   Extracciónthe aqueous phase is extracted with additional ether
6. 6
   ExtracciónThe total extract
7. 7
   Lavadois washed successively with water and saturated sodium chloride solution
8. 8
   Secadodried over potassium carbonate
9. 9
   Concentraciónfreed of volatile matter by concentration at reduced pressure
10. 10
    Otroto give an oil, λ maxMeOH

Procedimiento

To a stirred solution of 5.59 g. (24.6 mmoles) of 4-hydroxy-2-(6-carboxyhexyl) cylopent-2-en-1-one (Example 122) and 20.7 g. (2.46 mmoles) of dihydropyran in 100 ml. of methylene chloride at 20° C. is added 47 mg. (0.246 mmoles) of p-toluenesulfonic acid monohydrate in one portion. The temperature is maintained at 20°-25° C. by cooling and is stirred for one hour at that temperature. The solution is diluted with 200 ml. of ether and poured into a mixture of 40 ml. of saturated sodium bicarbonate solution, 40 ml. of saturated sodium chloride solution, and 80 ml. of water. The phases are separated, and the aqueous phase is extracted with additional ether. The total extract is washed successively with water and saturated sodium chloride solution, dried over potassium carbonate, and freed of volatile matter by concentration at reduced pressure to give an oil, λ maxMeOH. = 223 mu (9500); ν max. 1730 (ester carbonyl group), 1705 (ketone carbonyl group), and 1030 cm-1 (tetrahydropyranyloxy groups).

Fuente