合成路线1

Ethyl levulinate (I) was reacted with one equivalent of methylmagnesium bromide to produce 5,5-dimethyldihydrofuran-2-one (II). Friedel-Crafts condensation of (III) with benzene in the presence of AlCl3 afforded 4,4-dimethyl-1-tetralone (III) which, after nitration and reduction furnished the aminotetralone (V). This was converted to iodide (VI) upon diazotization, followed by treatment with KI. Methyl 4-vinylbenzoate (VIII) was obtained by alkylation of the corresponding carboxylic acid (VII) with MeI in the presence of DBU. Coupling of this olefin (VIII) with iodide (VI) was carried out using palladium diacetate and tetrabutylammonium chloride at 70 C to yield the diaryl ethylene derivative (IX). Subsequent addition of phenylmagnesium bromide to (IX) produced the tertiary alcohol (X). Finally, dehydration of (X) using p-toluenesulfonic acid, followed by basic hydrolysis, provided the title compound.