| Some fluorinated cyclobutenes and their derivatives (1959) | |||||||||||||||||
Abstract | |||||||||||||||||
| Cyclobutene structures were established for the cycloaddition products of 1-ethynylcyclohex-l-ene with trifluorochloroethylene or difluorodichloroethylene. The orientations of the addends were in accord with theories developed previously. Hydrolysis of the fluorinated cyclobutenes with sulfuric acid gave halogen-substituted cyclohex1encyclobutenones as well as cyclohex-1-enylcyclobutadienoquinone. Some halide displace merit reactions of the adducts were found to give, in general, products corresponding to reaction by SN2 mechanisms. Trifluro-2-chlaro-3-(cyclox-1-enyl)-cyclobutene gave Dials-Alder adducts with maleic anhydride and dicarbethoxyacetylene. 1,1-Difluoro-2,4-dicloro-3-(cyclohex-1-enyl)-cyclobutene with triethylamine underwent dehydrohalogenation and afforded, by means of an unusual rearrangements, 2-fluoro-1,3-dichloro-5,6,7,8-tetrahydronaphthalene. The nuclear magnetic resonance (NMR) spectra of the fluorinated cyclobutenes and cyclobutenones showed spectra which were anomalous in terms of simple NMR theory but which could be explained by assumption of cross-ring spin-spin coupling between hydrogen and fluorine. | |||||||||||||||||
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