Tandem intramolecular wittig and claisen rearrangement reactions in the thermolysis of 2-methyl-2-phenoxy-propionyl-cyanomethylenetriphenylphosphoranes: synthesis of substituted 2H-1-benzopyrans and benzofurans
作者:H. Rehman、Jampani Madhusudana Rao
DOI:10.1016/s0040-4020(01)87711-5
日期:1987.1
The preparation and thermolysis in vacuum of 2-niethyl-2-phenoxypropionyl-cyanomethylenetriphenylphoephoraane and derivatives containing methyl-methoxy- and chloro- substituents in the phenoxy ring is reported. The method merges the preparation of phenyl propargyl ethers by intramolecular Wittig reaction and their Claisen rearrangement into one step. The final products were the corresponding 2H-1-benzopyran
报道了在真空中2-苯甲基环中含有甲基-甲氧基和氯-取代基的2-乙基-2-苯氧基丙酰基-氰基亚甲基三苯基菲花烷及其衍生物的制备和热解。该方法将通过分子内维蒂希反应及其克莱森重排制备苯基炔丙基醚的步骤合并为一个步骤。最终产物是相应的2H-1-苯并吡喃或苯并呋喃或两者的混合物。衍生自含有2-甲基苯氧基的叶立德的炔丙基醚不仅生成4-氰基-2,2,8-三甲基-2H-1-苯并吡喃,而且生成7-氰基-6-异吡啶基亚基-1-甲基-三甲基[3.2 .1.0 2,7 ] -辛-3-烯-8-酮,为次要产物。