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13C NMR chemical shifts of heterocycles. Empirical substituent effects in 5-halomethyl-5-hydroxy-4,5-dihydroisoxazoles

✍ Scribed by Marcos A. P. Martins; Anna C. L. Martins

Publisher
John Wiley and Sons
Year
1994
Tongue
English
Weight
244 KB
Volume
32
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

Evaluation by empirically derived equations for the substituent effect (α, β, γ, δ) on the ^13^C NMR chemical shifts for C‐3, C‐4, C‐5 and halomethyl‐substituent carbon (C‐6) in 5‐halomethyl‐5‐hydroxy‐4,5‐dihydroisoxazoles (where C‐3 substituent=H), alkyl or phenyl, C‐4 substituent=H, alkyl or heteroalkyl and C‐5 substituent (=dior trihalomethyl), taking as reference 5‐trichloromethyl‐5‐hydroxy‐4,5‐dihydroisoxazole, is reported. From the calculated values for the α, β, γ and δ effects for each substituent it was possible to estimate the chemical shift of each carbon of the compounds.

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