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Carbon-13 n.m.r. analysis of selected strychnos alkaloids

✍ Scribed by J. Leung; Alan J. Jones

Publisher: John Wiley and Sons
Year: 1977
Tongue: English
Weight: 436 KB
Volume: 9
Category: Article
ISSN: 0749-1581
DOI: 10.1002/mrc.1270090610

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✦ Synopsis

Abstract

The carbon‐13 chemical shifts of strychnine and ten closely related analogues have been assigned and confirmed in several cases using selective proton decoupling techniques. Where additivity relationships are used the importance of having data on an array of structural analogues is emphasized. Quaternization at N‐19 exerts long range polarization effects throughout the molecular framework. The effects of N‐oxide formation on the carbon‐13 shifts of 5 to 9‐membered ring heterocycles and strychnine are discussed as aids to structural assignment. A Zwitterionic structure for strychnic acid is deduced.

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