Formation of 2,2-dimethylchroman-4-ones during the photoinduced rearrangement of some aryl 3-methyl-2-butenoate esters. A mechanistic insight
作者:Daniela Iguchi、Rosa Erra-Balsells、Sergio M. Bonesi
DOI:10.1016/j.tet.2016.02.039
日期:2016.4
Several aryl 3-methyl-2-butenoate esters upon irradiation lead to the formation of [1,3]-migrated photoproducts, phenol and, surprisingly 2,2-dimethylchroman-4-one derivatives. The starting photochemical reaction takes place from the singlet excited state of the ester and as a total mechanism two consecutive reaction pathways are proposed. The former involves the photo-Fries rearrangement of the esters
Bismuth(III) triflate catalyzed tandem esterification–Fries–oxa-Michael route to 4-chromanones
作者:Kevin Meraz、Krishna Kumar Gnanasekaran、Rup Thing、Richard A. Bunce
DOI:10.1016/j.tetlet.2016.10.005
日期:2016.11
An efficient tandem reaction approach is described to prepare 4-chromanones from electron-rich phenols and 3,3-dimethylacrylic acid or trans-crotonic acid in boiling toluene using 20 mol % bismuth(III) triflate as the catalyst. The reaction is also successful from the corresponding aryl esters of each of these acids under the same conditions. The procedure is convenient to perform, and 25–90% yields
Synthesis and reactivity of some 4-bromo- 2H-chromenes and 2H-thiochromenes
作者:Christopher D Gabbutt、David J Hartley、John D Hepworth、B.Mark Heron、Magan Kanjia、M.Moshfiqur Rahman
DOI:10.1016/s0040-4020(01)86967-2
日期:1994.2
synthesis of 4-bromo- 2H-chromenes and 2H-thiochromenes and of 1-bromo-3,4-dihydronaphthalene from the corresponding ketones and PBr3 is described. In some instances, significant quantities of the phosphonic acids (3) are isolated. Conversion of the bromo compounds to the lithio derivatives provides access to a wide range of novel 4-substituted 2H-chromenes and 2H-thiochromenes.
Singh, Om V.; George, Varughese; Kapil, Randhir S., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1995, vol. 34, # 10, p. 856 - 864
作者:Singh, Om V.、George, Varughese、Kapil, Randhir S.
DOI:——
日期:——
Livingstone et al., Journal of the Chemical Society, 1958, p. 2422