Synthesis of pyridines by thermolysis of 4a,7a-dihydrocyclopenta[e][1,2]oxazines
Abstract
The dihydro-oxazines (1) are converted into pyridines (2) when they are heated at 200°C, whereas the benzo-derivative (7) gives 2-naphthyl phenyl ketone; a mechanism is proposed which involves electrocyclic opening of the oxazine rings.