The first total synthesis of gambierol, a marine polycyclic ether toxin, has been achieved. Highly efficient synthesis of the ABC and EFGH ring fragments allowed us to prepare those two advanced intermediates in multi-gram quantities. The key feature of the present total synthesis is the B-alkyl Suzuki-Miyaura coupling tactics, which culminated in the union of the advanced intermediates and convergent synthesis of the octacyclic polyether core. Introduction of the sensitive triene side chain via Pd (PPh₃) 4/CuCl/LiCl-promoted Stille coupling was conducted at the final step of the synthesis.
The present total synthesis supplied useful quantities of gambierol and its structural analogues for detailed biological studies : an interesting observation was gained through pathological studies. Also, preliminary structure-activity relationship studies revealed that the functionalities present in the H ring and unsaturated side chain are crucial for potent toxicity against mice.