Conformational analysis of 2-substituted methylenecyclohexanes and 3-substituted cyclohexenes and the anomeric effect

1977 ◽  
Vol 55 (6) ◽  
pp. 1015-1023 ◽  
Author(s):  
Jean Lessard ◽  
Phan Viet Minh Tan ◽  
Robert Martino ◽  
John K. Saunders
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Double Bond ◽  
Magnetic Resonance ◽  
Conformational Analysis ◽  
Methoxy Group ◽  
Anomeric Effect ◽  
Magnetic Resonance Data ◽  
Electronegative Substituent ◽  
Axial Conformer ◽  
Resonance Data

The analysis of the 13C and 1H nuclear magnetic resonance data of 2-substituted methylenecyclohexanes and 3-substituted cyclohexenes demonstrates that a double bond stabilizes the axial conformer for an electronegative substituent. Introduction of a methoxy group on the double bond further increases the relative stability of the axial conformer. These results are interpreted in terms of the 'double bond – no bond' resonance.

Methods to Determine Phytopharmaceuticals in Tobacco and Tobacco Products. 4th Report: A Procedure to Determine Vamidothion and its Metabolites/Methoden zur Bestimmung von Phytopharmaka in Tabak und Tabakerzeugnissen: IV. Mitteilung: Ein Bestimmungsverfahren fuer Vamidothion und seine Metaboliten

1977 ◽  
Vol 9 (2) ◽  
Author(s):  
A.N. Sagredos ◽  
R. Moser
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Acetic Acid ◽  
Magnetic Resonance ◽  
Aluminium Oxide ◽  
Nuclear Magnetic Resonance Data ◽  
Gas Chromatograph ◽  
Tobacco Products ◽  
Magnetic Resonance Data ◽  
Resonance Data

AbstractBased on previous work (7) a method to simultaneously determine vamidothion [I], vamidothion-sulfoxide [II] and vamidothion sulfone [III] in tobacco has been developed. The compounds are extracted with water/acetone/acetic acid from the tobacco, cleansed over an aluminium oxide column and then determined on the gas chromatograph with the specific sulphur detector. Rates of recovery are 70 % - 92 %, the determination level is 0.1 ppm. Mass spectrometry and nuclear magnetic resonance data of vamidothion [I], vamidothion-sulfoxide [ II ] and vamidothion-sulfone [III] are given.

Lignans of western red cedar (Thuja plicata Donn). VI. Dihydroxythujaplicatin methyl ether

1967 ◽  
Vol 45 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Harold MacLean ◽  
Koji Murakami
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Methyl Ether ◽  
Degradation Products ◽  
Parent Compound ◽  
Thuja Plicata ◽  
Red Cedar ◽  
Magnetic Resonance Data ◽  
Resonance Data ◽  
Thuja Plicata Donn

Proof of structure is presented for another lignan of the thujaplicatin series, 2,3-dihydroxy-2-(4″-hydroxy-3″,5″-dimethoxybenzyl)-3-(4′-hydroxy-3′-methoxybenzyl)-butyrolactone (I) (dihydroxythujaplicatin methyl ether). Analytical and spectral (ultraviolet, infrared, and nuclear magnetic resonance) data on derivatives and degradation products, in addition to the parent compound, are presented.

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