Partially fluorinated heterocyclic compounds. Part 17 [1]. The preparation of fused 2H-pyran derivatives from polyfluoroaryl and -heteroaryl prop-2-enyl ethers with potassium fluoride via an electrocyclisation reaction. A novel [1,5] sigmatropic proton shift during the reaction of pentafluorophenyl prop-2-enyl sulphide with potassium fluoride
作者:Gerald M. Brooke
DOI:10.1016/s0022-1139(00)81169-0
日期:1983.5
A new synthesis of fused 2-pyran derivatives via an electrocyclisation reaction is described which is based on a novel route to o-quinomethide-type precursors. These transient materials are formed by the dehydrofluorination (with KF) in dipolar aprotic solvents of the Claisen rearrangement intermediates produced by the thermolyses of polyfluoroaryl and -heteroaryl prop-2-enyl ethers. 5,6,7,8- Tetr
描述了一种通过电环化反应合成稠合的2-吡喃衍生物的新方法,该方法基于一种新的合成邻甲基喹啉类前体的途径。这些瞬态材料是在聚氟芳基和-杂芳基丙-2-烯基醚的热解产生的克莱森重排中间体的偶极非质子溶剂中通过脱氟化氢(用KF)形成的。5,6,7,8-四氟-2--1-苯并吡喃(4)是由D 6回流的C 6 F 5-醚(1)形成的,而5,6,7,8,9,10-六氟-2 -萘并[2,1-b]吡喃(6)是从155-162°的环丁砜中的2-萘醚(5)获得的。2,4,5,6-四氟-3-吡啶醚(8)在环丁砜中于182°得到6,7,8-三氟-2的混合物-吡喃并[3,2-b]吡啶(10)(34%)和5,6,8-三氟-2-吡喃并[2,3-c]吡啶(12)(1%),但2,3,将5,6-四氟吡啶基醚脱烷基成4-羟基吡啶。由五氟苯基丙-2-烯硫醚(13)生成的邻喹二甲基中间体通过新颖的[1,5]σ质子转移异构化,然后环化为4