合成路线图解说明: The tetrahydronaphthalene derivative (III) was prepared by condensation of 1-bromo-2-ethoxybenzene (II) with 2,5-dichloro-2,5-dimethylhexane (I) in the presence of AlCl3. Lithium-bromine exchange in (III), followed by treatment with trimethyl borate and acid quenching, provided boronic acid (IV). This was subjected to palladium-catalyzed coupling with 3-bromo-3-buten-1-ol (V) to afford the homoallylic alcohol (VI). A Simmons-Smith reaction of (VI) with chloroiodomethane and diethylzinc furnished the cyclopropyl alcohol (VII), which was further oxidized to aldehyde (VIII) employing PCC. Horner-Emmons condensation of aldehyde (VIII) with phosphonate (IX) gave rise to the dienoate ester (X). Finally, basic hydrolysis of the ester function of (X) yielded the corresponding carboxylic acid. |