p-Toluenesulfonic acid → HCID 54446076, compound

Participants

Reaction Steps

3,4-dihydro-6-methoxy-1(2H)-naphthalenone (198 g) was dissolved in 2000 ml of toluene under argon and treated in succession with 193 ml of 3-buten-2-ol, 206 ml of 2,2-dimethoxypropane and 1.9 g of p-toluenesulphonic acid. The reaction mixture was boiled at reflux for 20 hours, treated with a further 175 ml of 3-buten-2-ol and 180 ml of 2,2-dimethoxypropane and boiled for a further 50 hours. After cooling the solution was washed with 500 ml of saturated sodium hydrogen carbonate solution, the aqueous phase was extracted once with 600 ml of ethyl acetate, the organic phases were combined, dried with MgSO4 and freed from solvent. The residue, 269 g of brown oil, was chromatographed on 3000 g of silica gel with hexane/diethyl ether (5:1) as the eluent. There were obtained 147 g (57%) of 2-(2-butenyl)-3,4-dihydro-6-methoxy-1(2H)-naphthalenone which was processed without further purification.

Provenance & Evidence