合成路线1

The condensation of verbenone (I) with 1-bromo-3-methyl-2-butene (II) by means of t-BuOK in DME, followed by ozonolysis of the aliphatic double bond gives acetaldehyde (III), which is isomerized with UV light in methanol to the chrysanthenone derivative (IV). The condensation of (IV) with ethyl propynoate (V) by means of LDA in THF, followed by silylation with TMSCl affords the silylated 4-hydroxy-2-pentynoate (VI), which is cyclized by means of Me2CuLi in ethyl ether giving the methanonaphthalene derivative (VII). The oxidation of the secondary OH group of (VII) with Dess Martin periodinane (DMP) yields the ketoester (VIII), which is hydroxylated with Davis' oxaziridine to the ketonic dihydroxyester (IX). The reduction of the ester group of (IX) with LiAlH4 in ethyl ether affords the tetrahydroxy compound (X), which is protected by silylation with TBDMS-Cl and imidazole and ketalization with PPTS and 2-methoxypropene providing the silylated acetonide (XI). The rearrangement of (XI) by means of MCPBA, followed by silylation with Tips-OTf gives (XII) with the A-B-bicycle of Taxol. The hydroxylation of (XII) with t-BuOK and oxygen, followed by reduction of its ketonic group with NaBH4 yields the trihydroxy compound (XIII), which is stereoselectively reduced with H2 and Crabtree catalyst, silylated with TMSCl and treated with triphosgene to afford the cyclic carbonate (XIV). The oxidation of (XIV) with pyridinium chlorochromate (PCC) in dichloromethane gives the carbaldehyde (XV), which is condensed with methoxymethyl(triphenyl)phosphorane to yield the acetaldehyde derivative (XVI). The selective silylation of (XVI) with Tes-Cl, followed by oxidation of the remaining secondary OH group with Dess Martin periodinane (DMP) and methylenation acetaldehyde CH2 group with Me2N-CH2-I affords the substituted propenoic aldehyde (XVII).