Реакция #742250

Уравнение реакции

3-[5-methyl-2-(tetrahydro-pyran-2-yloxy)-phenyl]-acrylic acid ethyl ester

p-toluenesulfonic acid

→

colourless crystals

Выход 71.0%

(E)-3-(2-Hydroxy-5-methyl-phenyl)-acrylic acid ethyl ester

Выход 71.0%

Растворители

ethanol

Условия реакции

Обработка

1. 1
   КонцентрированиеThen the reaction mixture was concentrated
2. 2
   workup.ADDITIONthe residue was diluted with ether
3. 3
   Промывкаwashed with saturated sodium bicarbonate and brine
4. 4
   Другоеdried
5. 5
   Другоеevaporated to dryness
6. 6
   ДругоеThe resulting yellow solid was recrystallized

Методика

A solution of 193.7 g 3-[5-methyl-2-(tetrahydro-pyran-2-yloxy)-phenyl]-acrylic acid ethyl ester (Bunce, R., Moore, J., Org. Prep. Proc., 29(3), 293 (1997)) and 2 g p-toluenesulfonic acid in 2.5 l of ethanol was stirred at room temperature for 24 hours. Then the reaction mixture was concentrated and the residue was diluted with ether, washed with saturated sodium bicarbonate and brine, dried and evaporated to dryness. The resulting yellow solid was recrystallized to yield 97.7 g of colourless crystals.

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