Abstract: | The synthesis of 1-(2-propynyl)pyridinium salts 3 described. Compounds 3 react with a second pyridine molecule, in the presence of the corresponding hydrochloride, to form products of type 4, Certain bases cause the 1-(2-propynyl)pyridinium salts 3 to rearrange into 1-propadienylpyridinium salts. 5 . Diethylamine converts compounds 3 into 1-acetonylpyridinium salts 8 . Moreover, treatment of 3 or 5 with sodium methoxide gives enol ether sof type 9, which can be hydrolyzed to teh ketones 8 . Addition of bromine to some of teh unsaturated compounds is also reported. |