Total Synthesis of CoibacinD by Using Enantioselective Allylation and Metathesis Reactions

The first asymmetric total synthesis of coibacinD, a metabolite isolated from the marine cyanobacterium cf. Oscillatoria sp., was achieved in six steps starting from simple hept-6-en-1-ol. The synthetic strategy was based on a chiral Brønsted acid catalyzed enantioselective allylboration and a Ru-carbene complex catalyzed sequential ring-closing and cross-metathesis strategy. The recorded spectroscopic data and the sign of the optical rotation of the synthesized coibacinD were in agreement with the published data for the isolated compound, which confirmed the proposed structure and absolute configuration.