反应详情

A suspension of 13.7 g of 4-(4-hydroxyphenyl)cyclohexanone in 350 ml of ethylene chloride was heated to reflux for 3 hours with 11.6 ml of ethylene glycol and 1.6 g of Amberlyst® 15 (strongly acidic ion exchang resin, Fluka AG) while stirring and separating water. Thereafter, the brown reaction solution was cooled to room temperature and washed twice with 200 ml of water each time. The aqueous phases were backextracted with 200 ml of methylene chloride. The organic phases were dried over sodium sulphate, filtered and concentrated on a rotary evaporator. The brown crystals obtained (17.4 g) were dissolved in 50 ml of hot ethyl acetate. The solution was treated with 50 ml of hexane and left to crystallize in a water bath. The precipitate was filtered off under suction and dried at 50° C., there being obtained 12.4 g of crude product as brown crystals. Working-up of the mother liquor gave a further 4.8 g of crude product. The crude product was purified by chromatography on silica gel with methylene chloride/acetone (volume ratio firstly 97:3, then 95:5) at 0.4 bar. Recrystallization of the orange, crystalline product from ethyl acetate/hexane (vol. 1:2) gave 15.0 g of 4-(1,4-dioxa-8-spiro[4.5]decyl)phenol as yellow-orange crystals with m.p. 151.7°-152.6° C.

1. temperaturewas heated
2. customseparating water
3. washwashed twice with 200 ml of water each time
4. dry with materialThe organic phases were dried over sodium sulphate
5. filtrationfiltered
6. concentrationconcentrated on a rotary evaporator
7. customThe brown crystals obtained (17.4 g)
8. waitleft
9. customto crystallize in a water bath
10. filtrationThe precipitate was filtered off under suction
11. customdried at 50° C.
12. customthere being obtained 12.4 g of crude product as brown crystals
13. customWorking-up of the mother liquor gave a further 4.8 g of crude product
14. customThe crude product was purified by chromatography on silica gel with methylene chloride/acetone (volume ratio firstly 97:3
15. customRecrystallization of the orange, crystalline product from ethyl acetate/hexane (vol. 1:2)