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13CC13 coupling constants in dimethyl phthalate and phthalic anhydride. Determination of signs—III

✍ Scribed by P. E. Hansen; A. Berg

Publisher
John Wiley and Sons
Year
1976
Tongue
English
Weight
240 KB
Volume
8
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

Relative signs of ^13^C^13^C coupling constants between ring carbons and carbonyl carbons in dimethyl phthalate and phthalic anhydride, ^13^C‐labelled in both carbonyl groups, have been determined. The two‐and three‐bond coupling constants are shown to be positive, whereas four‐bond coupling constants are negative. Substituent effects on carbon‐carbon couplings due to a carboxyl group have been determined and effects of 5‐membered ring formation in phthalic anhydride have been observed.

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