Electron-impact-induced hydrogen migration in organic molecules I-Substituent effects in the mass spectra of pivlanilides

1975 ◽  
Vol 10 (3) ◽  
pp. 196-199 ◽  
Author(s):  
D. V. Ramana ◽  
M. Vairamani ◽  
S. Kala
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Organic Molecules ◽  
Substituent Effects ◽  
Hydrogen Migration

The fragmentation of organic molecules under electron-impact—III: The mass spectra of some substituted thioureas

1970 ◽  
Vol 4 (S1) ◽  
pp. 81-88 ◽  
Author(s):  
M. A. Baldwin ◽  
Alicja M. Kirkien ◽  
A. G. Loudon ◽  
Allan Maccoll
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Organic Molecules

E. Radiation Chemistry of Diphenylpicrylhydrazyl (DPPH), IV. The Mass Spectra of Some Aromatic Hydrazines. Comparison of Radiolytic and Photolytic Fragmentations

1976 ◽  
Vol 31 (10) ◽  
pp. 1372-1375
Author(s):  
W. G. Filby ◽  
W. H. Kalus
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Radiation Chemistry ◽  
Hydrogen Migration ◽  
Radiation Induced

The mass spectra of some aryl hydrazines under electron impact are reported. In every case studied fragmentation occurs via fission of the weak hydrazyl N—N bond and hydrogen migration. Metastable ion data is presented in support of a proposed mechanism and some comparisons made between electron and radiation induced processes.

The fragmentation of organic molecules under electron-IMPACT—II. The mass spectra of tetronic acid and some of its derivatives

1968 ◽  
Vol 1 (6) ◽  
pp. 743-759 ◽  
Author(s):  
L. J. Haynes ◽  
Alicja Kirkien-Konasiewicz ◽  
A. G. Loudon ◽  
Allan Maccoll
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Organic Molecules ◽  
Tetronic Acid

Photochemical and mass spectrometric transformation of gibberellenic acid to 9-epiallogibberic acid

1984 ◽  
Vol 62 (10) ◽  
pp. 1996-1998 ◽  
Author(s):  
Hussain K. Al-Ekabi ◽  
Ghazi A. W. Derwish
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Mass Spectrometric ◽  
The Other ◽  
Positive Mass ◽  
Hydrogen Migration ◽  
Other Hand ◽  
Impact Fragmentation

Gibberellenic acid (2) reacted thermally in a modified immersion photochemical reactor, to give an intermediate triene (3). This triene then isomerized photochemically, via suprafacial [1,3]-hydrogen migration, to 9-epiallogibberic acid (5). On the other hand, comparison of the positive mass spectra of gibberellenic acid (2), allogibberic acid (4), and 9-epiallogibberic acid (5) showed that gibberellenic acid underwent electron impact fragmentation to the triene 3 cation. This cation then rearranged through suprafacial [1,3]-hydrogen migration to the 9-epiallogibberic acid (5) cation.

Mass spectra of 4,4-dimethyl-A-homo-4a,6-cholestadien-3-ols, 4,4-dimethyl-A-homo-5-cholestene-3,4a-diols and their derivatives

1982 ◽  
Vol 47 (10) ◽  
pp. 2768-2778
Author(s):  
Antonín Trka ◽  
Helena Velgová
Keyword(s):  
Carbon Atom ◽  
Electron Impact ◽  
Mass Spectra ◽  
Molecular Ions

Partial electron impact induced mass spectra are given of 3α-hydroxy-, 3β-hydroxy-, 3β-methoxy-, 3α-acetoxy- and 3β-acetoxy-4,4-dimethyl-A-homo-4a,6-cholestadienes, 3α,5α-epoxy-4,4-dimethyl-A-homo-5-cholestane, isomeric 4,4-dimethyl-A-homo-5-cholestene-3α(β),4aα(β)-diols, their 3-acetoxy derivatives and 3-methyl ethers. The fragmentation of the molecular ions of these substances involves the usual elimination of substituents (in the form of H2O, CH3OH, CH3COOH, CH2CO), but the most abundant and characteristic ions are products of the contraction of ring A (to a six- or five-membered one), accompanied by expulsion of a fragment containing the carbon atom C(4) with both methyls.

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