合成路线1

The intermediate carboxylic acid (XIII) was prepared as follows: 2-(4-Hydroxyphenyl)ethanol (VI) was selectively protected at the phenolic hydroxyl with benzyl bromide, yielding (VII). Subsequent oxidation of the aliphatic alcohol group of (VII) with Dess-Martin periodinane reagent provided aldehyde (VIII). Wadsworth-Emmons condensation of (VIII) with the sodium derivative of phosphonate (IX) furnished adduct (X), which was further hydrogenated over Pd/C to the saturated ester (XI). The phenolic hydroxyl group of (XI), which was concomitantly debenzylated in the preceding hydrogenation step, was further reprotected as the methoxymethyl ether (XII). Acid (XIII) was then obtained by basic hydrolysis of ester (XII).