In the Krohnke pyridine synthesis, pyridine is used as a catalyst of sort. One makes a pyridinium ketone which (with the help of ammonium acetate) loses a proton and attacks a Michael acceptor, to ultimately make a substituted pyridine. The ammonium ion provides the nitrogen for the substituted pyridine But the original molecule of pyridine is not the source of the pyridine ring in the final product. My question is would other heterocycles, such as oxazolium ketones or thiazolium ketones, be as effective? My tentative answer is that there might be more side reactions. For example, the hydrogen at C-2 of a thiazolium compound is somewhat acidic (the pKa of thiamin pyrophosphate is about 18). My interest is not so much in the Kronhke synthesis as it is in other Michael additions that such substituted ketones might do.