Synthesis of Azadirachtin: A Long but Successful Journey


  • We gratefully acknowledge the many co-workers who have worked on this project and the EPSRC (G.E.V. and A.B.), Alexander von Humboldt Foundation (E.B.), and Novartis (S.V.L.) for generous funding.


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22 Years in the making: Azadirachtin (1) was synthesized for the first time by a highly convergent approach, utilizing a Claisen rearrangement and a radical cyclization as key steps. End-game strategies relied on intermediate 2, which could be obtained by synthetic methods as well as by degradation of 1. Bn=benzyl, TBS=tert-butyldimethylsilyl.