[Cl:1][CH:2]=[C:3]1[CH:9]=[CH:8][C:7]2[CH:10]=[C:11]([CH:14]=[CH:15][CH2:16][CH2:17][C:18]3([CH3:23])OCC[O:19]3)[CH:12]=[CH:13][C:6]=2[O:5][CH2:4]1.CC(C)=O.C1(C)C=CC(S(O)(=O)=O)=CC=1>ClCCl.CC#N.CC#N.Cl[Pd]Cl>[Cl:1][CH:2]=[C:3]1[CH:9]=[CH:8][C:7]2[CH:10]=[C:11]([CH:14]=[CH:15][CH2:16][CH2:17][C:18](=[O:19])[CH3:23])[CH:12]=[CH:13][C:6]=2[O:5][CH2:4]16 mg (0.023 mmol) of bis(acetonitrile)palladium(II) chloride are added to 79 mg (0.237 mmol) of 3-(chloromethylene)-7-[4-(2-methyl-1,3-dioxolan-2-yl)-1-butenyl]-2,3-dihydro-1-benzoxepin, prepared according to example 74, in solution in 1.5 ml of dichloromethane. After stirring at ambient temperature for 3 hours, 0.5 ml of acetone and a catalytic amount of para-toluenesulfonic acid are added. The reaction medium is then stirred for 30 minutes. The crude reaction product is purified by chromatography on silica gel (ethyl acetate/heptane 10/90) to provide 55 mg (80%) of 6-[3-(chloromethylene)-2,3-dihydro-1-benzoxepin-7-yl]-5-hexen-2-one in the form of a mixture of isomers in an EZ/EE ratio (85/15) for the chloromethylene functional group; 1H NMR (300 MHz, CDCl3) EZ isomer: 2.18 (s, 3H), 2.45 (m, 2H), 2.61 (m, 2H), 4.86 (s, 2H), 6.10 (m, 1H), 6.33 (m, 4H), 6.96 (m, 3H).
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