Studies toward the Synthesis of Azadirachtin, Part 2: Construction of Fully Functionalized ABCD Ring Frameworks and Unusual Intramolecular Reactions Induced by Close‐Proximity Effects

The remarkable antifeedant agent and insecticide, azadirachtin (1), has, to date, escaped a total synthesis. The preparation of an advanced precursor has revealed some of the inner intricacies of this uniquely crowded and highly functionalized molecular architecture.