5 g (12.31 mmoles) of the compound from Example III, 3.7 ml (15.4 mmoles) of tributylamine, 6.6 ml (46.2 mmoles) of 1-heptene, 375 mg of tri-o-tolylphosphine (1.23 mmoles), and 138 mg of palladium(II) acetate (0.6 mmole) are stirred in 50 ml of dry DMF for 2.5 h at 100° C. The mixture is cooled to room temperature, 50 ml of ethyl acetate is added, and the mixture is washed 3 times with 50-ml portions of H2O. After drying over MgSO4, the organic phase is evaporated under vacuum, and the residue is chromatographed on silica gel with toluene/ethyl acetate 95:5 as eluant. The fractions containing the product are combined and the solvent is evaporated under vacuum. The initially oily residue is crystallized by stirring with 35 ml petroleum ether.
