合成路线1

The reduction of 4,4-dimethyltetrahydropyran-2-one (I) with iBuAlH in THF gives 4,4-dimethyltetrahydropyran-2-ol (II), which is condensed with phosphorane (III) in refluxing acetonitrile to yield the heptenoic ester (IV). The protection of the OH group of (IV) with Tbdms-Cl and imidazole affords the silyl ether (V), which is reduced at the double bond with H2 over Pd/C in ethyl acetate to provide the heptanoate ester (VI). The reduction of the ester group of (VI) with iBu2AlH in THF gives the primary alcohol (VII), which is protected with dihydropyran and PPTS, yielding the tetrahydropyranyl ether (VIII). The desilylation of (VIII) with TBAF in THF affords the heptanol derivative (IX), which by oxidation with tetrapropylammonium perruthenate (TPAP) in dichloromethane is converted into the aldehyde (X). The condensation of (X) with CBr4 and PPh3 in dichloromethane provides the dibromovinyl compound (XI), which is condensed with hexafluoroacetone (XII) by means of BuLi in THF to give the acetylenic alcohol (XIII). The deprotection of (XIII) with pyridinium p-toluenesulfonate (PPTS) in methanol yields the acetylenic diol (XIV), which is selectively reduced with H2 over Pd/C in ethyl acetate to afford the (Z)-ethylenic diol (XV). The oxidation of the primary alcohol of (XV) with pyridinium dichromate in dichloromethane provides the aldehyde (XVI), which is silylated with Tms-Cl, TEA and DMAP in dichloromethane to give the silylated unsaturated aldehyde (XVII).