STEREOCHEMICAL DIFFERENTIATION OF ISOMERIC TRINORBORNANE-2,3-DIOLS AND TRINORBORNANE-2,5-DIOLS BY CHEMICAL-IONIZATION MASS-SPECTROMETRY

Because stereoisomeric trinorbornane-2,3- and trinorbornane-2,5-diols cannot be distinguished under electron ionization, their differentiati on was investigated under chemical ionization. The spectra were record ed using ammonia, isobutane, methane, acetone and trimethyl borate as reagent gas. Although all the stereoisomers could be identified, the d ifferences between the cis-2,3-diols were minor. By contrast, the tran s-2,3- and 2-endo-5-endo-diol isomers were easily differentiated from their corresponding stereoisomers. Stereochemical effects were greates t under isobutane, acetone and trimethyl borate chemical ionization. T he collision-induced dissociation mass spectra of the [M + NH4]+ adduc t ions also allowed most of the stereoisomers to be distinguished.