SYNTHESIS OF 2-DIMETHYLAMINO-3-SUBSTITUTED 2H-PYRANS AND STUDY OF THEIR VALENCE ISOMERIZATION TO δ-DIMETHYLAMINO DIENONES

Article abstract of DOI:10.1007/BF00475681

It is shown that 2-dimethylamino-3-isopropyl(3-dimethylamino)-2H-pyrans are formed in the condensation of aminal acetals of α-isopropyl or α-dimethylamino-β-dimethylaminoacroleins with β-dicarbonyl compounds.It was observed by means of 1H and 13C NMR and UV spectroscopy that they do not undergo valence isomerization to δ-dimethylamino dienones.Under the influence of pulse photoexcitation the 2H-pyrans undergo reversible cleavage of the C-O bond and isomerization to the corresponding dienones.