Über Reaktionen mit Betain,XIV Darstellung von Trifluoracetyl-methylid-trifluoracetaten aus Betainen

The reaction of trimethylammonium acetic acid betaine (1) with trifluoroaceticanhydride (TFA) yielding trifluoroacetyl-N-methylide can be extended to triethylammonium acetic acid betaine (2), 2-pyridiniumpropionic acid betaine (9) andN,N-dimethyl-piperidinium-2-carboxylate betaine (14). Trigonelline and 3-pyridiniumpropionic acid betaine (11), however, do not react in this way. It follows that the formation of such ylides is only possible if the methylene or methine group of the betaines are flanked by ammonium and carboxylate group.

Herrn emer. o. Univ.-Prof. Dr. techn. Dr. hc.Otto Kratky, Institut für Feinstrukturforschung der Österr. Akademie der Wissenschaften und Forschungszentrum Graz, zur Vollendung des 80. Lebensjahres gewidmet.