Abstract
A total enantioselective synthesis of ectocarpin A, an oxylipin identified through the first hydroperoxide bicyclase activity of CYP5164A3 in brown algae, has been successfully completed in 12 steps starting from tetrahydro‐1H‐cyclopentafuranone. Key transformations include the creation of the chiral tetrahydro‐1H‐cyclopentafuranone, a diastereoselective epoxidation, an enzymatic desymmetrization of a 1,4‐diol, an epimerization, and both Wittig and Julia‐Kocienski olefinations to build the carbon framework of ectocarpin A.