1.3- dienyl-boron compound

Other functional groups containing group III-A elements have also been employed as sources of fluorinatcd compounds. Thus, 5-fluorocyclopenta-l,3-diene(21)can be obtained by reaction of (cyclopenta-2,4-dienyl)thalium with l-(chloromethyl)-4-lluoro-1,4-diazoniabicyclo[2.2.2]oc-tane bis(tetrafliioroboratc) in acetonitrile. The reaction of arylthalium(III) difluorides with boron trifluoride also yields the corresponding aryl fluorides (45-71... 

Reaction of the ArC,o unit with 1-pentynylmagnesium bromide occurred smoothly in tetrahyrofuran containing cuprous chloride without formation of alienic impurities. An analogous type of route was used for the synthesis of 1,3-dimethoxy-5-[(ZZ)-pentadec-8,11-dienyl]benzene, (15 2)-cardol dimethyl ether (ref. 105). For the synthesis of (15 2)-urushiol, 1,2-dihydroxy-3-[(ZZ)-penta-dec-8.11-dienyl]benzene and its dimethyl ether, 7-(2,3-dimethoxyphenyl)heptyl bromide and the corresponding 2,3-dihydroxy compound, obtained by demethylation with boron tribromide, have been used (ref. 149). 

---