Appendix—Notes on the nuclear-magnetic-resonance spectrum of ω-fluorodecanoic acid and of a fluoro-octadecenoic acid of unknown structure

Abstract

Fluoro-oleic acid from the seeds of Dichapetalum toxicarium (Sierra Leone) has been isolated pure in gram quantities. The terminal position of the fluorine has been proved by nuclear magnetic resonance. The cis-structure was confirmed by infrared spectrophotometry and the position of the double bond by the identification of o-fluorononanoic acid and of azelaic acid by gas chromatography after ozonization. The identification of U) -fluorononanoic acid confirmed the position of the fluorine. In the final purification another fluoro-fatty acid of much higher melting point has been separated in small amounts. It contains no double bond, and possibly 17 carbon atoms, but behaves biochemic-ally as a long-chain fatty acid with an even number of carbon atoms. Observations have been made of the ultraviolet spectra and of the toxicity to rats and to guinea-pig-kidney particles of both acids.