Interception of photochemical intermediate of thiazole derivatives. Formation and isomeristion of iminoazetine and azetinone intermediates

Abstract

Irradiation of 4-aminothiazolium salts (7) in the presence of tributylphosphine gave enaminonitriles 9) and benzoylacetonotrile (8) by isomerisation and hydration of the iminoazetine intermediates (11), while a similar irradiation of the mesoionic triphenylthiazolium-4-oate (1) gave the quinolinol (5) by isomerisation of the azetione intermediate (3).