Addition regioselective d'organometalliques α-insatures ou α-fonctionnels au chlorure de n-ethoxycarbonylpyridinium : synthese de dihydro-1,2 (ou -1,4) pyridines 2-(ou 4-)substituees.
Reaction of allylic tin reagents with nitrogen heteroaromatics activated by alkyl chloroformates: regioselective synthesis of .alpha.-allylated 1,2-dihydropyridines and change of the regioselectivity depending on methyl substituents at the allylic moiety