Total synthesis of (−)-elegansidiol by using an abnormal Beckmann fragmentation of Hajos ketone oxime as a key step

Abnormal Beckmann fragmentation of Hajos ketone oxime regioselectively forms of a chiral 1-oxygenated 2,2-dimethyl-4-methylene-cyclohexan skeleton. Using this transformation as a key step, the total synthesis of (−)-elegansidiol, an oxygenated mono-carbocyclic sesquiterpenoid, was achieved.