Über Reaktionen mit Betain, 13. Mitt.: Darstellung von trihalogenacetyl-methyliden und ihrer Salze aus Betainen

Reaction of the betaine1 and pyridinebetaine8 with trifluoroacetic anhydride yields the salts4a or9a and the yellow ylide5, respectively. In an analogous manner8 reacts with trichloroacetic anhydride to give11a. In a competitive reaction the trifluoroacetates6 and10 are also formed. Pyridinebetaine hydrochloride reacts similarily with trichloroacetic anhydride.

12. Mitt.:Wittmann H., Sobhi D., Petio F. A., Z. Naturf.31 b, 850 (1976).