74780-47-5Relevant articles and documents
1,3-Dipolar Character of Six-membered Aromatic Rings. Part 51. Cycloadditions of 1-(β-Benzoylvinyl)-3-oxidopyridiniums and Subsequent Transformations
Katritzky, Alan R.,Rahimi-Rastgoo, Soheila,Sabongi, Gebran J.,Fischer, Gerhard W.
, p. 362 - 371 (2007/10/02)
β-p-Chloro-, β-p-bromo-, and β-2-chloro-5-nitrobenzoyl-vinyl chloride react with 3-hydroxypyridine to give quaternary salts which with base give the corresponding betaines.These betaines undergo thermal dimerisation and cycloadditions with mono- and di-enes at the 2,6- and 2,4-positions, respectively.The site-, regio-, and stereo-selectivity of these cycloadditions are discussed with reference to MO predictions.The β-aroylvinyl substituents in the adducts can be hydrolytically removed.