作者:Tomio Shimizu、Yoshiyuki Hayashi、Susumu Ishikawa、Kazuhiro Teramura
DOI:10.1246/bcsj.55.2456
日期:1982.8
arylhydrazones of some 2-(alkenyloxy)benzaldehydes(or 1-naphthaldehydes) with Pb(OAc)4 leads, via the nitrilimine intermediates, to intramolecular 1,3-dipolar cycloadducts, 3-substituted 2-aryl-2,3,3a,4-tetrahydro[1]benzopyrano(or naphtho[1′,2′:5,6]pyrano)[4,3-c]pyrazoles, in 10–80% yields. In the presence of an excess of Pb(OAc)4, these cycloadducts were dehydrogenated to 3-substituted 2-aryl-2,4-dih
某些 2-(烯氧基)苯甲醛(或 1-萘醛)的芳基腙与 Pb(OAc)4 的反应通过腈亚胺中间体生成分子内 1,3-偶极环加合物,3-取代的 2-芳基-2, 3,3a,4-四氢[1]苯并吡喃(或萘并[1',2':5,6]吡并)[4,3-c]吡唑,产率10-80%。在过量 Pb(OAc)4 存在下,这些环加合物脱氢为 3-取代的 2-芳基-2,4-二氢[1]苯并吡喃(或萘并[1',2':5,6]吡喃) [4,3-c]吡唑。在大量过量的 Pb(OAc)4 存在下,一些吡唑被乙酰氧基化,得到相应的 4-乙酰氧基吡唑。根据前沿分子轨道 (FMO) 理论解释了烯基取代基对反应反应性的影响。