The carbon-13 nuclear magnetic resonance spectra of the antibiotic polyacetylenic nitrile, diatretyne 2 (7-cyanohept-trans-2-ene-4,6-diynoic acid), and related compounds

Abstract

The natural abundance carbon-13 chemical shifts of the nitrite ester (9; R = CH₃)(diatretyne 2 methyl ester) and a series of related acetylenic compounds have been measured and correlated with structure. The effect of the various substituents and the carbon–carbon triple bond on the chemical shift of the immediate carbon nuclei is discussed.