Acetic Acid → 1,4-Dimethoxy-5,6,8,9-tetrahydrobenzocyclohepten-7-one

Participants

Reaction Steps

3-[2-(2-tert-butoxycarbonylethyl)-3,6-dimethoxyphenyl]-propionic acid tert-butyl ester (6.33 g) was added dropwise to a refluxed solution of sodium hydride (578 mg) in dry toluene (60 ml) and dry tert-butyl alcohol (0.5 ml), and stirred for 3 hours. After cooling, to the reaction mixture glacial acetic acid was added dropwise followed by addition of ice water and extracted with ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate and evaporated in vacuo. To the residue were added methanol (50 ml) and 6N hydrochloric acid (15 ml), and this mixture was refluxed for 3 hours, poured into ice and extracted with ethyl acetate. The residue was chromatographed (hexane-ethyl acetate) over silica gel to afford 1,4-dimethoxy-5,6,8,9-tetrahydrobenzocyclohepten-7-one (2.99 g).

Provenance & Evidence