Both (±)-protoemetinol, its 3-epi-isomer and (±)-3-desmethyl protoemetinol have been prepared in five linear steps from a dihydroisoquinoline using a 6-exo-trig cyclisation of a vinyl radical in the key step. This novel and particularly short route has potential application in the synthesis of Alangium and Mitragyna alkaloids.
                                    (±)-proetetinol,其3- epi-异构体和(±)-3-desmethyl proetetinol都是在五个线性步骤中由二氢
异喹啉在关键步骤中使用
乙烯基的6- exo - trig环化制备的。这种新颖且特别短的路线在合成Alangium和Mitragyna
生物碱方面具有潜在的应用前景。