On the occasion of the 100th anniversary: Ernst Späth and his mescaline synthesis of 1919

Characterizing plant ingredients has been the main topic of chemical research at the University of Vienna since the beginning of the last half of the nineteenth century, especially at the IInd Chemical Institute (founded in 1870). The remarkable success in many fields of natural organic product structure elucidation was in part the result of the discovery of important identifying reactions of functional groups in organic molecules by Austrian chemists, e.g., Lieben´s iodoform test, the Herzig–Meyer´s method for the determination of methylamino groups or Zeisel´s method for the determination of methoxy groups in organic compounds. Ernst Späth was the most prominent exponent of the Viennese school of phytochemistry. He and his coworkers identified more than 120 phytochemical substances. His mescaline synthesis of 1919 has marked a milestone in the chemistry of organic natural products. Graphical abstract