Mass spectral fragmentation studies in usnic acid and related compounds

1974 ◽  
Vol 8 (1) ◽  
pp. 129-146 ◽  
Author(s):  
James P. Kutney ◽  
Ignacio H. Sanchez ◽  
Trevor H. Yee
Keyword(s):  
Usnic Acid ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Related Compounds

Electron Impact-Induced Fragmentations of 2-Benzothiazole Sulfenamides and Related Compounds. Correlation with Rubber Vulcanization Activity

1972 ◽  
Vol 45 (1) ◽  
pp. 160-172 ◽  
Author(s):  
K. T. Potts ◽  
E. G. Brugel ◽  
J. J. D'Amico ◽  
E. Morita
Keyword(s):  
Electron Impact ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Fragmentation Patterns ◽  
Related Compounds ◽  
Rubber Accelerators

Abstract A correlation has been made between the activity of commercial rubber accelerators and vulcanizing agents and their mass spectral fragmentation patterns.

THE MASS SPECTRAL FRAGMENTATION OF SULFENAMIDES AND RELATED COMPOUNDS

1976 ◽  
Vol 1 (2-3) ◽  
pp. 143-152 ◽  
Author(s):  
David N. Harpp ◽  
Thomas G. Back ◽  
James P. Snyder
Keyword(s):  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Related Compounds

The Mass Spectral Fragmentation of Perezone and Related Compounds

1997 ◽  
Vol 11 (8) ◽  
pp. 904-906
Author(s):  
Eduardo Cortés ◽  
Benjamín Ortiz ◽  
Rubén Sánchez-Obregón ◽  
Fernando Walls ◽  
Francisco Yuste
Keyword(s):  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Related Compounds

Mass spectral fragmentation reactions of a therapeutic 4-azasteroid and related compounds

2001 ◽  
Vol 12 (4) ◽  
pp. 385-398 ◽  
Author(s):  
David J. Burinsky ◽  
Jon D. Williams ◽  
Alan D. Thornquest ◽  
Scott L. Sides
Keyword(s):  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Fragmentation Reactions ◽  
Related Compounds

Alkaloids from Buxus sempervirens L. III. Mass spectral fragmentation

1965 ◽  
Vol 30 (8) ◽  
pp. 2869-2874 ◽  
Author(s):  
L. Dolejš ◽  
V. Hanuš ◽  
Z. Votický ◽  
J. Tomko
Keyword(s):  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Buxus Sempervirens

Triazolopyridine nucleosides. II. Glycosylations of 3-oxo-s-triazolo[4,3-a]pyridines with accompanying conversions into 2-oxo-s-triazolo[1,5-a]pyridine nucleosides

1977 ◽  
Vol 55 (5) ◽  
pp. 831-840 ◽  
Author(s):  
Brian Maurice Lynch ◽  
Suresh Chandra Sharma
Keyword(s):  
General Structure ◽  
Spectroscopic Properties ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
H Nmr ◽  
Pyridine Nitrogen ◽  
Methyl Derivatives ◽  
Fragmentation Patterns ◽  
Ribose Moiety ◽  
C Nmr

3-Oxo-s-triazolo[4,3-a]pyridine and various C-methyl derivatives (general structure 1) have been converted into the 2-β-D-ribofuranosyl species 2 and thence 4 via Friedel–Crafts catalyzed reaction with tetra-O-acetyl-β-D-ribofuranose, followed by deblocking. During the course of these reactions, rearrangements into the isomeric 3-β-D-ribofuranosyl-2-oxo-s-triazolo[1,5-a]-pyridines occur through ring-opening of the pyridine rings yielding species 3 and 5. The proportion of rearrangement products is dependent upon the position and number of the C-methyl substituents.Structural assignments for these compounds are based upon comparisons of spectroscopic properties (1H nmr, 13C nmr, uv) with model compounds from each isomeric series; structural assignments for these models are based on unequivocal mass-spectral fragmentation patterns. Unlike related triazolopyridine nucleosides with the ribose moiety attached to a pyridine nitrogen (Lynch and Sharma (1976)), there are no unusual aspects in the conformations of the nueleosides of types 4 and 5.

Mass Spectra of β-Keto Esters

1972 ◽  
Vol 50 (16) ◽  
pp. 2707-2710 ◽  
Author(s):  
Larry Weiler
Keyword(s):  
Mass Spectra ◽  
Carbonyl Groups ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Keto Esters ◽  
Fragmentation Patterns

The mass spectra of several γ-substituted β-keto esters have been recorded and interpreted. The fragmentation patterns are compared to those of α-substituted β-keto esters and are found to be very useful in differentiating the α- and γ-substituted isomers. The mass spectral fragmentation schemes are dominated by cleavages α to the carbonyl groups and by McLafferty rearrangements.

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