Electron ionization mass spectra of monosaccharide O-methyloxime trifluoroacetates

✍ Scribed by Mark A. Andrews; Elinor Norton

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 760 KB
• Volume: 199
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(90)84260-2

✦ Synopsis

Electron ionization mass spectra for trifluoroacetate (TFA) derivatives of aldose, ketose, and deoxyaldose O-methyloximes are reported. Typical fragmentation patterns include loss of F, CH,O, CF,CO, or CF,CO, fragments from the generally observable parent ion, as well as cleavage between each of the sugar C-C chain bonds. The most intense ions result from loss of trifluoroacetic acid and/or trifluoroacetic anhydride from these primary fragments. Suitable high-mass and fragmentation ions are present to make this technique a useful structural probe, During the preparation of fructose TFA O-alkyloximes, partial conversion to I-chloro-1-deoxyfructose derivatives is observed due to displacement of an Otrifuoroacetyl group by chloride ions present in the reaction mixture. ' -185) = 100.00 = 35 840 ion counts, -= less than 10 ion counts, satd. = saturated], I (a) = relative intensity of anti-oxime ions [I (m/z = 185) = 100.00 = 12 192 ion counts].