Reaction #742250

Reaction equation

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

p-toluenesulfonic acid

→

colourless crystals

Yield 71.0%

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

Yield 71.0%

Solvents

ethanol

Conditions

Workup

1. 1
   ConcentrationThen the reaction mixture was concentrated
2. 2
   workup.ADDITIONthe residue was diluted with ether
3. 3
   Washwashed with saturated sodium bicarbonate and brine
4. 4
   Otherdried
5. 5
   Otherevaporated to dryness
6. 6
   OtherThe resulting yellow solid was recrystallized

Procedure

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.

Source