Atmospheric pressure chemical ionization multi-stage mass spectrometry in the characterization of stereoisomeric synthons of cyclopropane amino acids

✍ Scribed by Cristoni, Simone; Cativiela, Carlos; Jim�nez, Ana I.; Traldi, Pietro

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 203 KB
• Volume: 35
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(200002)35:2<199::aid-jms930>3.0.co;2-6

✦ Synopsis

The mass spectrometric behaviour of (1S,2R)-, (1R,2R)-, (1R,2S)-and (1S,2S)-2-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]-1-spiro-f4 [2 -phenyl-5 (4 H)-oxazolone]g cyclopropane (2) and (1S,2R)-, (1R,2R)-, (1R,2S)-and (1S,2S)methyl-1-benzamido-2-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]cyclopropanecarboxylate (3) was studied under atmospheric pression ionization conditions and by multi-stage mass spectrometric (MS n ) experiments performed with an ion trap. Interestingly, by using methanol as solvent, compounds 2 lead to [M Y H Y CH 3 OH] Y ions which, as proved by collisional experiments, exhibit the same structure of the corresponding compound 3. MS/MS of [MH] Y ions allows a clear characterization of the different stereoisomers, which give rise to specific fragmentation pathways, rationalized with respect to the structure of the neutral molecules.