Реакция #93053

Уравнение реакции

H2SO4

campholenic aldehyde

methyl-ethyl ketone

potassium hydroxide

→

(E)-3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-3-penten-2-one

Выход 60.4%

Растворители

water

methanol

Условия реакции

Обработка

1. 1
   workup.WAITThe mixture was kept at -5° for 24 hours
2. 2
   Другоеat room temperature
3. 3
   КонцентрированиеAfter concentration under reduced pressure
4. 4
   workup.DISSOLUTIONthe obtained residue was dissolved in 200 ml of water
5. 5
   workup.ADDITIONdiluted with petrol ether 30/50
6. 6
   Промывкаwashed until neutrality
7. 7
   Другоеdried
8. 8
   Концентрированиеconcentrated
9. 9
   Другое189.3 G of a raw material was thus obtained which
10. 10
    workup.DISTILLATIONon distillation with a Vigreux column of 15 cm length

Методика

152 G (1.0 M) of campholenic aldehyde having a purity of about 75% were added dropwise under stirring in 15-20 minutes to a mixture cooled at -5/-10° of 400 g (6.1 M) of methyl-ethyl ketone, 1025 g (35 M) of methanol, 30.5 g (0.54 M) of potassium hydroxide and 380 g of water. The mixture was kept at -5° for 24 hours, then at room temperature for the same period and neutralized thereupon with H2SO4 to 62.5%. After concentration under reduced pressure, the obtained residue was dissolved in 200 ml of water, diluted with petrol ether 30/50, washed until neutrality, dried and concentrated. 189.3 G of a raw material was thus obtained which on distillation with a Vigreux column of 15 cm length gave 144.6 g of (E)-3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-3-penten-2-one having a purity of 86% (yield 60.4%).

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