Reacción #742250

Ecuación de reacción

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

p-toluenesulfonic acid

→

colourless crystals

Rendimiento 71.0%

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

Rendimiento 71.0%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   ConcentraciónThen the reaction mixture was concentrated
2. 2
   workup.ADDITIONthe residue was diluted with ether
3. 3
   Lavadowashed with saturated sodium bicarbonate and brine
4. 4
   Otrodried
5. 5
   Otroevaporated to dryness
6. 6
   OtroThe resulting yellow solid was recrystallized

Procedimiento

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.

Fuente