合成路线1

The title compound was synthesized by two related methods. Stobbe condensation between 4-hydroxybenzaldehyde (I) and diethyl succinate (II) in the presence of NaOEt afforded the benzylidenesuccinate monoester (III). Coupling of (III) with cis-hexahydroisoindoline (IV) gave the amidoester (V). The phenolic hydroxyl group of (V) was then alkylated with tosylate (VI) to provide the corresponding ether (IX). Alternatively, intermediate (IX) was obtained by initial alkylation of 4-hydroxybenzaldehyde (I) with tosylate (VI). The resultant alkyloxy benzaldehyde (VII) was then subjected to Stobbe condensation with diethyl succinate (II) to afford the benzylidenesuccinate (VIII), which was further coupled with the bicyclic amine (IV) to produce (IX). Finally, ester (IX) obtained by either synthetic method was hydrolyzed with NaOH to furnish the target carboxylic acid.