Total synthesis of cyclotripeptidic natural products anacine, aurantiomide C, polonimides A and C, and verrucine F

The total synthesis of cyclotripeptidic natural products possessing a central piperazino[2,1-b]quinazolin-3,6-dione core is described, through an original strategy involving the pivotal cyclocondensation of an electrophilic homoserine lactone intermediate. The alkylidene group was spontaneously installed by autooxidation during the cyclocondensa-tion process, while the propionamide side-chain was introduced through the nickel-catalyzed aminocarbonylation of a bromoethyl intermediate. This last reaction is unprecedented on such highly functionalized intermediates. Finally, we explored structural modifications and interconversions of the natural products. Overall, this work led to anacine, au-rantiomide C, polonimide A and C, and verrucine F.