This compound was prepared by two ways starting from 3-(3-oxo-2,3-dihydropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine (I). Alkylation of (I) with 2-chlorocyclohexanone (II) in the presence of NaH in DMF gave diketone (V). Alternatively, condensation of (I) with epoxycyclohexane and NaH in DMF at 127 C yielded the ketoalcohol (IV) as a mixture of cis and trans isomers, which were separated by column chromatography. The major trans isomer was then oxidized with pyridinium dichromate to the diketone (V). Reaction of this diketone with the sodium salt of triethyl phosphonoacetate (VI) in toluene at 100 C afforded a mixture of unsaturated esters (VII) and (VIII), which were subsequently submitted to hydrolysis with NaOH. Then, column chromatography of the mixture provided the desired endocyclic unsaturated acid.