反応 #62708

反応方程式

2,5-dimethylhex-3-ene-2,5-diol

n-hexanal

toluene

→

2-pentyl-4,4,7,7-tetramethyl-4,7-dihydro-1,3-dioxepin

収率 70.3%

溶媒

water

反応条件

後処理

1. 1
   温度was refluxed
2. 2
   その他was separated off in the course of 5.5 h
3. 3
   workup.WAITThe mixture was then left
4. 4
   温度to cool
5. 5
   workup.ADDITION10 ml of a 25% strength aqueous sodium hydroxide solution were added
6. 6
   洗浄the mixture was washed neutral with a little water
7. 7
   その他the toluene was removed under reduced pressure at from 50° to 60° C
8. 8
   その他The residue obtained
9. 9
   workup.DISTILLATIONwas distilled under 0.1 mbar

実験手順

A mixture of 720 g (5 moles) of 2,5-dimethylhex-3-ene-2,5-diol, 3 g of p-toluenesulfonic acid, 500 g (5 moles) of n-hexanal and 1 l of toluene was refluxed, and the resulting water of reaction (115 ml) was separated off in the course of 5.5 h. The mixture was then left to cool, 10 ml of a 25% strength aqueous sodium hydroxide solution were added, the mixture was washed neutral with a little water and the toluene was removed under reduced pressure at from 50° to 60° C. The residue obtained was distilled under 0.1 mbar to give 796 g of 2-pentyl-4,4,7,7-tetramethyl-4,7-dihydro-1,3-dioxepin of boiling point 75° C./0.1 mbar.

出典