作者:Kenichi Somekawa、Ryusuke Imai、Ryuichi Furukido、Sanetada Kumamoto
DOI:10.1246/bcsj.54.1112
日期:1981.4
Sensitized photoirradiations of 2-pyridones with tetrachloroethylene or trichloroethylene gave chlorinated 3-azabicyclo[4.2.0]oct-4-en-2-ones (1) and 2-azabicyclo[4.2.0]oct-4-en-3-ones (2 and 3), 7,7,8-trichloro-2-methyl-2-azabicyclo[2.2.2]oct-5-en-3-one (4), and other products. The reaction with 1,1-dichloroethylene, though, gave only 7,7-dichloro-3-azabicyclo[4.2.0]oct-4-en-2-one. 1, 2, 3, and 4 were reduced by zinc to give 7,8-dichloromethyl-3-azabicyclo[4.2.0]octa-4,7-dien-2-one, 2-azabicyclo[4.2.0]octa-4,7-dien-3-ones (7) and 6-chloro-2-methyl-2-azabicyclo[2.2.2]octa-5,7-dien-3-one respectively. Then, 7 thermally gave valence isomers, 7-azabicyclo[4.2.0]octa-2,4-dien-8-ones, which were β-lactams.
用四氯乙烯或三氯乙烯对2-吡啶酮进行敏化光照射反应,得到了氯化的3-氮杂双环[4.2.0]辛-4-烯-2-酮(1)和2-氮杂双环[4.2.0]辛-4-烯-3-酮(2和3)、7,7,8-三氯-2-甲基-2-氮杂双环[2.2.2]辛-5-烯-3-酮(4)及其他产物。然而,与1,1-二氯乙烯的反应仅产生了7,7-二氯-3-氮杂双环[4.2.0]辛-4-烯-2-酮。1、2、3和4在锌的还原作用下,分别生成了7,8-二氯甲基-3-氮杂双环[4.2.0]辛-4,7-二烯-2-酮、2-氮杂双环[4.2.0]辛-4,7-二烯-3-酮(7)和6-氯-2-甲基-2-氮杂双环[2.2.2]辛-5,7-二烯-3-酮。然后,7在热条件下生成了价异构体7-氮杂双环[4.2.0]辛-2,4-二烯-8-酮,这些都是β-内酰胺。