合成路线1

The silylation of the epoxide (VII) with Tbdms-Cl gives the silyl ether (VIII), which is condensed with alkynyl aluminum (X) (obtained by reaction of 5-(tert-butyldimethylsilyloxy)-1-pentyne (IX) with dimethylaluminum and BuLi) in toluene, followed by treatment with HOAc to yield the unsaturated diol (XI). The controlled hydrogenation of the triple bond of (XI) with H2 over Lindlar catalyst affords the (Z)-olefin (XII), which is treated with Ts-Cl to provide the monotosylate (XIII). The silylation of the remaining OH group of (XIII) with Tms-OTf gives the fully protected triol (XIV), which is treated with NaI in refluxing acetone to yield the iodide (XV). The condensation of (XV) with the chiral amide (XVI) by means of BuLi in THF/HMPA affords the adduct (XVII), which by elimination of the chiral auxiliary by reduction with DIBAL in dichloromethane, followed by controlled oxidation with SO3/pyridine, provides the aldehyde (XVIII). The aldol condensation of aldehyde (XVIII) with the intermediate oxoacid (VI) by means of LDA in THF gives the heptadecanoic acid (XIX), which is fully silylated with Tbdms-OTf and lutidine, yielding the silylated silyl ester (XX). Selective elimination of the Tms and ester-Tbdms- groups with aqueous HOAc affords the hydroxyacid (XXI).