HALOCARBENES AS DIAGNOSTIC-TOOLS FOR MASS-SPECTRAL LOCALIZATION OF DOUBLE-BONDS

Different halocyclopropanes prepared by cycloaddition of halocarbenes to olefins by phase-transfer reactions have been analyzed by gas chrom atography/mass spectrometry (GC/MS). Starring from CCl2-adducts, the i nvestigations have been extended to bromine- and fluorine-containing c yclopropanes. As reaction partners, a group of olefins, containing dif ferent alkyl substituents, have been selected. Thereby, special attent ion has been paid to smooth reaction conditions, high reaction yield a nd simple handling. The suitability for mass spectral analysis is disc ussed. Fragmentation pathways and diagnostic potential are evaluated. Best results have been obtained by addition of bromofluorocarbene to d ouble bonds. The resulting bromofluorocyclopropanes are considered to be the most promising derivatives for mass spectral localization of do uble bonds.