3-Methyl-but-2-enoic acid 4-bromo-phenyl ester → 2H-1-Benzopyran-2-one, 6-bromo-3,4-dihydro-4,4-dimethyl-

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Reaction Steps

To a stirred, ice cooled suspension of 11.5 g (86.3 mmol) of aluminum chloride in 200 ml of methylene chloride was added a solution of 11.0 g (43.1 mmol) of (4-bromophenyl) 3,3-dimethyl-acrylate in 100 ml of methylene chloride. The mixture was then stirred at room temperature for 20 hours and then poured into ice/brine mixture. The mixture was extracted with methylene chloride and the combined orgainc extracts were washed with water, brine and dried (MgSO4). The solvent was removed in-vacuo and the resulting residue purified using flash chromatography (SiO2 ; 4% ethyl acetate in hexanes) to give the title compound as a yellow oil.

Provenance & Evidence