Chemistry of Succinimido Esters.XX

GC-MS analysis of N-arylcarbonyl-O, O'-bis (TMS) derivatives (4) of synthetic dihydrosphingosines (1) was conducted to establish a convenien method for determining the erythro and threo isomers of (1) by mass spectrometry. The structures of fragment ions were determined by comparing the mass spectra of (4) with different substituents in the aryl group and carbon chain of (1). The structures were indicated based on differences in mass numbers of (4) -d18 and (4) h18 derivatives [N-arylcarbonyl-O, O'-bis (TMS) -d18 and O, O'-bis (TMS) -h18 derivatives of (1)]. One characteristic difference was relative intensity (RI) at m/z=M-103; the relative intensities of threo compounds (RI=30-70%) exceeded those of erythro isomers (RI<10%). The ratios, γ=RI (M-103) /RI (M-15), of threo compounds were greater than those of the erythro isomers. Values γ (threo) /γ (erythro) were from 3 to 7. From these results, it should be possible to determine the erythro and threo isomers of (1) by mass spectrometry in the form of (4).