Derivatives and reactions of glutaconaldehyde—IX : Substitution reactions in the glutaconaldehyde anion. assignment of structure of a free glutaconaldehyde

Substitution in the glutaconaldehyde anion takes place at C 2 or 4, demonstrated by deuterium exchange and by preparation of the mono- and dichloro or bromo and the monoiodo glutaconaldehyde sodium salts and their respective enol esters. The stable 2-iodoglutaconaldehyde was suggested to have the all-trans structure of 2-iodo-5-hydroxy-trans-2, trans-4-pentadienal. The preparations from the monochloro and bromo glutaconaldehyde anions of 3-halogenopyridines and thiopene-2-carboxaldehyde have been reinvestigated.