Diels-Alder reactions of nitro-2(1H)-pyridones with 2,3-dimethyl-1,3-butadiene.
Diels-Alder (DA) reactions of 3- or 5-nitro-2(1H)-pyridones and nitro-2(1H)-pyridones containing a methoxycarbonyl group with 2,3-dimethyl-1,3-butadiene were examined. The DA reactions of 3-nitro-2(1H)-pyridones in this paper represent, to the best of our knowledge, the first report of DA reactions of 3-substituted 2(1H)-pyridones and consequent production of isoquinolones. Performing the same reactions with 5-nitro-2(1H)-pyridones yielded quinolones. DA reactions of 2(1H)-pyridones with nitro and methoxycarbonyl groups produced isoquinolones, quinolones and phenanthridones (the double DA adducts), aromatized or hydrogenated. The substituent effect was evaluated by calculating the activation energy, using the ab initio MO method.
Fujita
R
R
Tohoku Pharmaceutical University, Sendai, Japan. refujita@tohoku-pharm.ac.jp
Watanabe
K
K
Nishiuchi
Y
Y
Honda
R
R
Matsuzaki
H
H
Hongo
H
H
D000475:Alkenes / Q000737:chemistry; D002073:Butanes / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D013058:Mass Spectrometry; D009574:Nitro Compounds / Q000737:chemistry*; D011728:Pyridones / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D000475:Alkenes; D002073:Butanes; D009574:Nitro Compounds; D011728:Pyridones; C436724:2,3-dimethyl-1,3-butadiene