ISSN:
0749-1581
Keywords:
13C NMR chemical shifts
;
13C NMR substituent effect transmission
;
1,7,7-Trimethyl-3-[(E)-2′-arylethenyl]-2-oxabicyclo[4.4.0]deca-3,5-dienes
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
13C NMR chemical shifts were determined for all carbons in a number of 1,7,7-trimethyl-3-[(E)-2′-arylethenyl]-2-oxabicyclo[4.4.0]deca-3,5-dienes [aryl = C6H5, C6H4CH3-p, C6H4F-p, C6H4Cl-p, C6H4Br-p, C6H4CN-p, C6H4NO2-p, C6H4OCH3-p, C6H3(OCH3)2-m, p and α-furyl]. Substituent chemical shift (Δδ13C) values for C-1, C-3, C-4, C-5, C-6, C-1′, C-2′, C-3′ and C-4′,8′ were correlated with various Hammett parameters by singleparameter analysis. The correlations revealed that the substituent effects are transmitted across three π-bonds in conjugation with the aryl ring. Dual-substituent-parameter treatment of the substituent chemical shifts revealed that resonance plays a major role in the substituent effect transmission. Hammett parameters were also derived for the α-furyl substituent.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260280304
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