Stereochemical effects in the electron ionization mass spectra of cycloalkane-(alkene)-fused 2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-5-ones and 3,4-dihydro-2H,6H-pyrimido[2,1-b]thiazin-6-ones

Kalevi Pihlaja, Marja Himottu, F. Fülöp, Imre Huber, G. Bernáth, Vladimir Ovcharenko

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Stereochemical effects on the electron-impact (EI)-induced fragmentation of cis/trans- and diendo/diexo-fused stereoisomers of several 2,3-dihydrothiazolo[3,2-a]pyrimidin-5-ones and 3,4-dihydropyrimido[2,1-b]thiazin-6-ones annelated to various saturated and unsaturated carbocycles were studied. The retro-Diels-Alder fragmentations of the hydrocarbon rings were found to be of low to medium stereospecificity. A number of highly selective fragmentation processes, some of them involving a McLafferty rearrangement as an initial step, were discovered, and several criteria for the differentiation between stereoisomers of cyclohexane-, cyclohexene-, norbornane-, and norbornene-fused compounds were proposed. The fragmentation pathways were confirmed by accurate mass measurements and by metastable ion spectra.

Original languageEnglish
Pages (from-to)721-726
Number of pages6
JournalRapid Communications in Mass Spectrometry
Volume10
Issue number6
Publication statusPublished - 1996

Fingerprint

Cycloparaffins
Stereoisomerism
Alkenes
Ionization
Norbornanes
Electrons
Hydrocarbons
Ions
pyrimidine

ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy

Cite this

@article{d7b126271ffe41bd804c9d25f3ae5055,
title = "Stereochemical effects in the electron ionization mass spectra of cycloalkane-(alkene)-fused 2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-5-ones and 3,4-dihydro-2H,6H-pyrimido[2,1-b]thiazin-6-ones",
abstract = "Stereochemical effects on the electron-impact (EI)-induced fragmentation of cis/trans- and diendo/diexo-fused stereoisomers of several 2,3-dihydrothiazolo[3,2-a]pyrimidin-5-ones and 3,4-dihydropyrimido[2,1-b]thiazin-6-ones annelated to various saturated and unsaturated carbocycles were studied. The retro-Diels-Alder fragmentations of the hydrocarbon rings were found to be of low to medium stereospecificity. A number of highly selective fragmentation processes, some of them involving a McLafferty rearrangement as an initial step, were discovered, and several criteria for the differentiation between stereoisomers of cyclohexane-, cyclohexene-, norbornane-, and norbornene-fused compounds were proposed. The fragmentation pathways were confirmed by accurate mass measurements and by metastable ion spectra.",
author = "Kalevi Pihlaja and Marja Himottu and F. F{\"u}l{\"o}p and Imre Huber and G. Bern{\'a}th and Vladimir Ovcharenko",
year = "1996",
language = "English",
volume = "10",
pages = "721--726",
journal = "Rapid Communications in Mass Spectrometry",
issn = "0951-4198",
publisher = "John Wiley and Sons Ltd",
number = "6",

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TY - JOUR

T1 - Stereochemical effects in the electron ionization mass spectra of cycloalkane-(alkene)-fused 2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-5-ones and 3,4-dihydro-2H,6H-pyrimido[2,1-b]thiazin-6-ones

AU - Pihlaja, Kalevi

AU - Himottu, Marja

AU - Fülöp, F.

AU - Huber, Imre

AU - Bernáth, G.

AU - Ovcharenko, Vladimir

PY - 1996

Y1 - 1996

N2 - Stereochemical effects on the electron-impact (EI)-induced fragmentation of cis/trans- and diendo/diexo-fused stereoisomers of several 2,3-dihydrothiazolo[3,2-a]pyrimidin-5-ones and 3,4-dihydropyrimido[2,1-b]thiazin-6-ones annelated to various saturated and unsaturated carbocycles were studied. The retro-Diels-Alder fragmentations of the hydrocarbon rings were found to be of low to medium stereospecificity. A number of highly selective fragmentation processes, some of them involving a McLafferty rearrangement as an initial step, were discovered, and several criteria for the differentiation between stereoisomers of cyclohexane-, cyclohexene-, norbornane-, and norbornene-fused compounds were proposed. The fragmentation pathways were confirmed by accurate mass measurements and by metastable ion spectra.

AB - Stereochemical effects on the electron-impact (EI)-induced fragmentation of cis/trans- and diendo/diexo-fused stereoisomers of several 2,3-dihydrothiazolo[3,2-a]pyrimidin-5-ones and 3,4-dihydropyrimido[2,1-b]thiazin-6-ones annelated to various saturated and unsaturated carbocycles were studied. The retro-Diels-Alder fragmentations of the hydrocarbon rings were found to be of low to medium stereospecificity. A number of highly selective fragmentation processes, some of them involving a McLafferty rearrangement as an initial step, were discovered, and several criteria for the differentiation between stereoisomers of cyclohexane-, cyclohexene-, norbornane-, and norbornene-fused compounds were proposed. The fragmentation pathways were confirmed by accurate mass measurements and by metastable ion spectra.

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VL - 10

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JO - Rapid Communications in Mass Spectrometry

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