Biogenetic Relationships between Annonaceous Acetogenins:  Squamocin Is Not a Precursor of Chamuvarinin Based on a Semisynthetic Study

In the course of reactivity studies on squamocin (1), a highly cytotoxic acetogenin from the plant family Annonaceae, two diastereomers, 3 and 4, of chamuvarinin (2) were synthesized. Based on this, a plausible relative configuration was proposed for 2, demonstrating the absence of any biogenetic link between 1 and 2. The new analogues 3, 4, and 7 were also tested for their ability to induce apoptosis.