Reaction #52872

Reaction equation

(+/−) ethyl 4-[[(5,5-dimethyl-8-hydroxy-8-(carbethoxy)-5,6,7,8-tetrahydronaphthalen-2-yl)carbonyl]oxy]benzoate

p-toluenesulfonic acid monohydrate

→

title compound

Ethyl 4-[[(5,5-dimethyl-8-(carbethoxy)-5,6-dihydronaphthalen-2-yl)carbonyl]oxy]benzoate

Solvents

benzene

Conditions

Workup

1. 1
   TemperatureThe solution was heated
2. 2
   Temperatureto reflux under a Dean-Stark trap for 3 h
3. 3
   OtherThe solvent was removed under reduced pressure

Procedure

To a solution of (+/−) ethyl 4-[[(5,5-dimethyl-8-hydroxy-8-(carbethoxy)-5,6,7,8-tetrahydronaphthalen-2-yl)carbonyl]oxy]benzoate (Compound E54, 35.0 mg, 0.077 mmol) in 10 mL benzene was added a catalytic amount (approximately 2 mg) of p-toluenesulfonic acid monohydrate. The solution was heated to reflux under a Dean-Stark trap for 3 h, and then cooled to room temperature and stirred overnight. The solvent was removed under reduced pressure and the title compound isolated from the residue by column chromatography (10% EtOAc-hexanes).

Source