The ent-kaurenoids are the major component of Isodon diterpenes and exhibited a wide range of biological activities,such as anti-bacteria,anti-cancer and immunosuppressive activities with low toxicity.The ent-kaurenoids contain the tetacyclic core(ABCD ring system) of ent-kaurene with different oxygenation and cleavage patterns.Recently,we have successfully developed a dual-mode Lewis acid induced cascade cyclization approach for a concise synthesis(6 steps from 2 and 3 in 24 ％yield) of tetracyclic intermediate 1,which has been demonstrated to be a versatile intermediate for the total syntheses of different classes of Isodon diterpenes including the C20-oxygenated and 6,7-seco-ent-kaurenoids.