U.v. irradiation of 4-ethyl-2,6-dimethylpyrylium perchlorate in water gives 2-ethyl-4-methyl-5-oxohex-2-enal (8) and syn- and anti-5-ethylidene-2,3-dimethylcyclopent-2-enone (9), all three products probably being formed via an oxoniabenzvalene intermediate (6).
在
水中对
高氯酸4-乙基-2,6-二
甲基吡啶鎓进行紫外线照射,得到2-乙基-4-甲基-5-氧杂己基-2-烯醛(8)以及顺-和抗-5-亚乙基-2,3-二甲基
环戊烯- 2-烯酮(9),所有三种产物可能是通过苯并氧杂戊环中间体(6)形成的。