These chemicals are the major product when iminium salts are heated, then quenched with water. One subclass of these compounds is the 5-amino-2,4-pentadienals, which can be formed by ring opening of pyridinium salts when secondary amines are substituted for primary ones in a certain reaction. Terminal z-alkenes result from the reaction of one of these compounds with a triphenyl phosphonium ylide. An alcohol and a carboxylic acid are the products in the base-catalyzed (*) disproportionation of these compounds. These reactants in the Cannizzaro reaction can be produced by the Stephen synthesis, 
These chemicals are the major product when iminium salts are heated, then quenched with water. One subclass of these compounds is the 5-amino-2,4-pentadienals, which can be formed by ring opening of pyridinium salts when secondary amines are substituted for primary ones in a certain reaction. Terminal z-alkenes result from the reaction of one of these compounds with a triphenyl phosphonium ylide. An alcohol and a carboxylic acid are the products in the base-catalyzed (*) disproportionation of these compounds. These reactants in the Cannizzaro reaction can be produced by the Stephen synthesis, and can be identified by the formation of a precipitate in a Tollens' test. Including the aforementioned Zincke variety, FTP, identify these compounds which contain a terminal carbon bonded to a hydrogen atom and double bonded to an oxygen atom – a terminal carbonyl group – and which can be distinguished via the silver mirror test from ketones.
These chemicals are the major product when iminium salts are heated, then quenched with water.
{aldehyde}s [prompt on {carbonyl}s]