合成路线1

Michael addition of itaconic acid (II) to 4-tert-butylaniline (I), and further lactamization afforded pyrrolidone carboxylic acid (III). This was esterified with H2SO4 in MeOH, and the resulting methyl ester (IV) was reduced to alcohol (V) with NaBH4 in boiling tetrahydrofuran. Optical resolution of (V) was achieved by condensation with phthalic anhydride (VI) to give amide (VII), followed by coupling of the remaining carboxylic acid group of (VII) with chiral alpha-methylbenzyl amine (VIII) yielding (IX). After separation of the diastereomeric mixture (IX), hydrolysis of the phthalate ester furnished the required (S)-alcohol (X) (2). Mesylate (XI), prepared from alcohol (X) and MsCl in the presence of Et3N, was condensed with methyl 4-hydroxybenzoate (XII) to afford ether (XIII). Then, basic hydrolysis of the methyl ester of (XIII) provided the title compound.