Synthesis of novel spinosyn A analogues by Pd-mediated transformations.

The concept of modern crop protection demands for a continuous supply of new or modified established pesticides to avoid the development of serious resistances. Recent reports on the insecticidal spinosyns 1 and 2 show that also this class of pest managing agents is increasingly exposed to the formation of resistances. The synthesis of new derivatives is therefore highly desirable. We describe in this paper a convergent approach towards novel enantiopure spinosyn A analogues of type 3, which is based on investigations of structure-activity relationships and employs a twofold Heck reaction as key step for the preparation of the tricyclic backbone assembly.