Carbon-13 nuclear magnetic resonance studies. XVIII. Carbon-13 nuclear magnetic resonance study of the interchange-transfer rearrangement of .alpha.-acyloxy ketones

1971 ◽  
Vol 93 (24) ◽  
pp. 6702-6703 ◽  
Author(s):  
J. B. Stothers ◽  
Iris S. Y. Wang ◽  
D. Ouchi ◽  
E. W. Warnhoff

1965 ◽  
Vol 18 (9) ◽  
pp. 1405 ◽  
Author(s):  
IRC Bick ◽  
DHS Horn

From a nuclear magnetic resonance study of the tautomerism of tasmanone and 1,1,3,3-tetramethylphloroglucinol (syncarpic acid), it is deduced that tasmanone consists of a mixture of tautomers (I) and (II) with the tautomer (I) present in the larger proportion. Similarly it is deduced that the tautomers of agglomerone (XI; R = CHMe2), 3-acetyl-O-methylfilicinic acid (XI R; = Me), ceroptene (XI; R = CH=CHPh), and usnic acid (XIII) with the extended conjugation are the more stable and populated ones.



1977 ◽  
Vol 55 (3) ◽  
pp. 447-453 ◽  
Author(s):  
A. K. Cheng ◽  
J. B. Stothers ◽  
C. T. Tan

The bicyclo[2.2.2]octan-2-one and -[3.2.1]octan-6-one skeletons are interconvertible under strongly basic conditions. Their α,α-dimethyl derivatives in tert-Buo−/tert-BuOH at 185 °C undergo very slow interconversion by β-proton abstraction. Using 2H nmr the stereoselectivity of deuterium incorporation at the β-methylene sites was established. The relative reactivities of β-methyl exchange in the [3.2.1] system were also determined. As models for this process, exchange in the α,α,α′,α′-tetramethyl derivatives of the monocyclic ketones, C5–C8, was also studied.







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