Addition of nitrile oxides to benzocyclobutene. Generation of 3-(p-methoxyphenyl)benzo[3,4]cyclobuta[1,2-d]isoxazole, a heterocyclic analogue of biphenylene
作者:Thomas L. Gilchrist、Eric E. Nunn、Charles W. Rees
DOI:10.1039/p19740001262
日期:——
3-Dipolar cycloaddition to cyclobutadienes has been observed for the first time in the reaction of benzocyclobutene with benzonitrile oxides; the products, 3-aryl-3a, 7b-dihydrobenzo[3,4]cyclobuta[1,2-d]isoxazoles (1), were isolated in good yields. Adducts were not obtained from cyclobutadiene or benzocyclobutene with several other 1,3-dipolar reagents; possible reasons for this are discussed. Monobromination
在苯并环丁烯与苄腈氧化物的反应中,首次观察到1,3-偶极环加成环丁二烯。分离出3-芳基-3a,7b-二氢苯并[3,4]环丁[1,2- d ]异恶唑(1)的收率。没有从环丁二烯或苯并环丁烯与其他几种1,3-偶极试剂中获得加合物。讨论了可能的原因。3-对甲氧基苯基加合物(1c)的单溴化,然后用叔丁醇钾进行脱氢溴化,得到3-(对甲氧基苯基)苯并[3,4]-环丁[1,2- d ]异恶唑(2)迅速形成叔丁醇3a,7b加成产物(6)的中间体。