Total chemical synthesis of 2-ethenyl-3,5-dimethylpyrazine and 3-ethenyl-2,5-dimethylpyrazine
作者:Toshinari H Kurniadi、Rachid Bel Rhlid、Marcel-A Juillerat、Thierry Gefflaut、Jean Bolte、Ralf G Berger
DOI:10.1016/s0040-4020(03)00948-7
日期:2003.8
2-ethenyl-3,5-dimethylpyrazine 1 and 3-ethenyl-2,5-dimethylpyrazine 2 were synthesized via a new chemical route. The key steps of the synthesis involve cyclocondenzation of 1-[bicyclo[2.2.1]5-hepten-2-yl]-1,2-propanedione and 1,2-propanediamine, aromatization of the resulting 5,6-dihydropyrazines, and subsequent Retro-Diels–Alder reaction to generate pyrazines 1 and 2. Pyrazine 1, a powerful odorant, was
通过新的化学路线合成了香气化合物2-乙烯基-3,5-二甲基吡嗪1和3-乙烯基-2,5-二甲基吡嗪2。合成的关键步骤包括1- [双环[2.2.1] 5-庚-2-基] -1,2-丙二酮和1,2-丙二胺的环缩合,所得5,6-二氢吡嗪的芳构化,以及随后发生Retro-Diels-Alder反应,生成吡嗪1和2。当将内基-1- [双环[2.2.1] 5-庚-2-基] -1,1,2-丙二酮用作内衬时,可获得过量(8:2)的强效吡嗪1。