Chemical ionization mass spectra of acetals of ?-D-glycopyranosylnitromethanes

✍ Scribed by Kov�?ik, Vladim�r; P�toprst�, Vladim�r; Petru?, Ladislav; Ovcharenko, Vladimir; Pihlaja, Kalevi

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 85 KB
• Volume: 35
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(200005)35:5<634::aid-jms989>3.0.co;2-5

✦ Synopsis

O-Isopropylidene and O-benzylidene acetals of common 2, 6-anhydro-1-deoxy-1-nitroalditols (beta-D-glycopyranosylnitromethanes) derived from D-glucose, D-galactose and D-mannose were studied by chemical ionization mass spectrometry (CIMS) using methane, isobutane, ammonia or pyridine as reaction gas. Production of M+H adduct ions dominates in the case of methane or isobutane possessing proton affinity values PA = 552 or 683 kJ mol(-1), respectively. The collision-induced dissociation time-of-flight product ion spectra of M+H ions differ characteristically according the stereochemical arrangement of the pyranoid ring. These differences can be helpful when assigning stereochemical arrangements for the pyranoid ring. The dominant process in ammonia (PA = 853 kJ mol(-1)) CIMS for most of the compounds studied is the production of the cluster ions M+NH(4). The cluster M+pyridineH ions are observable only for substances possessing the O-benzylidene group (PA of pyridine = 924 kJ mol(-1)). Copyright 2000 John Wiley & Sons, Ltd.