合成路线1

Esterification of 3-(4-hydroxyphenyl)propionic acid (I), followed by alkylation of the phenolic hydroxyl, provided methyl 3-(4-benzyloxyphenyl)propionate (II), which was hydrolyzed to the corresponding carboxylic acid (III) by means of LiOH. Coupling of carboxylic acid (III) with the chiral auxiliary (S)-4-benzyl-2-oxazolidinone (IV) gave the oxazolide (V), which was subjected to diastereoselective alkylation with tert-butyl bromoacetate (VI), yielding (VII). Subsequent removal of the chiral auxiliary group of (VII) using lithium hydroperoxide afforded the (R)-acid (VIII). Alkylation of the dianion of acid (VIII) with allyl bromide (IX) and further epimerization in the presence of LDA and Et2AlCl furnished the anti-dialkylated succinate (X). The carboxyl group of (X) was then alkylated using benzyl bromide and DBU to produce the corresponding benzyl ester (XI). Olefin (XI) hydroboration followed by oxidative work-up gave rise to the primary alcohol (XII). This was acylated with 4-nitrophenyl chloroformate (XIII) to provide the activated carbonate (XIV).