His synthesis of tropinone, a precursor of cocaine, in 1917 was not only a big step in alkaloid chemistry but also showed that tandem reactions in a one-pot synthesis are capable of forming bicyclic molecules.
Hans syntese af tropinon, en precursor til kokain, i 1917 var ikke bare et stort skridt inden for alkaloid-kemi, men vist også at tandem reaktioner i en one-pot syntese kan danne bicykliske molekyler.