Collect. Czech. Chem. Commun. 1987, 52, 2687-2698

Michael reaction of methylenemalonaldehydes: Synthetic approach to 4H-pyran-5-carboxaldehydes and 2-amino-4H-pyran-5-carboxaldehydes

Dalimil Dvořák, David Šaman, Jana Hodačová, Vladimír Král and Zdeněk Arnold

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


Base-catalyzed addition of β-dicarbonyl compounds to methylenemalonaldehydes led to tetracarbonyl compounds II which were dehydrated in an acid medium to 4H-pyran-5-carboxaldehydes III. In the addition of compounds containing a nitrile group, the primarily formed addition products were immediately cyclized to give directly 2-amino-4H-pyran-5-carboxaldehydes V.