scholarly journals The 1-Methylene Derivatives of [7](2,6)Pyridinophane. Preparative and Conformational Studies

1972 ◽  
Vol 45 (6) ◽  
pp. 1881-1883 ◽  
Author(s):  
Shinsaku Fujita ◽  
Kazuo Imamura ◽  
Hitosi Nozaki
Keyword(s):  
Conformational Studies ◽  
Derivatives Of

Conformational Studies on 1,3-Dioxepanes. Part IV. Applications of Geminal Coupling Constants to Conformational Analysis of 1,3-Dioxepanes

1974 ◽  
Vol 52 (24) ◽  
pp. 4062-4071 ◽  
Author(s):  
T. Bruce Grindley ◽  
Walter A. Szarek
Keyword(s):  
Conformational Analysis ◽  
Coupling Constants ◽  
Conformational Studies ◽  
Vicinal Coupling Constants ◽  
Geminal Coupling ◽  
Derivatives Of ◽  
Acetal Carbon

The magnitude of —OCH2O— group geminal H,H coupling contants, the size of the vicinal coupling constants, and the tenets of conformational analysis were used to establish that in solution the conformation of the 1,3-dioxepane rings in derivatives of 1,3:2,5-di-O-methylenemannitol and 2,5-O-methylenemannitol is predominantly the twist-chair in which the C2 axis passes through the acetal carbon.

scholarly journals Derivatives of benzo[b]furan. Part I. Conformational studies of khellinone and visnaginone

2012 ◽  
Vol 23 (5) ◽  
pp. 1573-1584 ◽  
Author(s):  
Tomas Pena Ruiz ◽  
Aleksandra Drzewiecka ◽  
Anna E. Koziol ◽  
Manuel Fernandez Gomez ◽  
Kinga Ostrowska ◽  
...  
Keyword(s):  
Conformational Studies ◽  
Derivatives Of

Concerning the mechanism of in toluene and its derivatives

1983 ◽  
Vol 61 (12) ◽  
pp. 2785-2789 ◽  
Author(s):  
Ted Schaefer ◽  
Reino Laatikainen
Keyword(s):  
Coupling Constants ◽  
Spin Coupling ◽  
Similar Magnitude ◽  
Conformational Preference ◽  
Conformational Studies ◽  
Methyl Group ◽  
Ring Substituent ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling ◽  
Derivatives Of

On the basis of the observed five-bond spin–spin coupling constants between the α protons and the meta ring protons in the 2,6-difluoro derivatives of toluene, ethylbenzene, and cumene, it is argued that [Formula: see text] in toluene can be written as A[Formula: see text]. A and B are of the same sign and of very similar magnitude. In consequence, [Formula: see text] cannot be used to measure the conformational preference of the methyl group. However, [Formula: see text] and [Formula: see text] in α-substituted toluene derivatives will be useful in conformational studies. [Formula: see text] in toluene derivatives varies between 0.30 and 0.46 Hz and some patterns in its ring substituent dependence can be gleaned from some fifty precise values.

Sign in / Sign up

Export Citation Format

Share Document