Synthetic Studies of Polycyclic Terpenoids Using the Intramolecular Aldol-Type Cyclization Reaction

Abstract

Our four recent synthetic studies of polycyclic terpenoids using the intramolecular aldol type cyclization reaction are described. (i) Asymmetric total synthesis of tricyclic diterpenoid spirocurcasone using an intramolecular aldol condensation to construct the bicyclic ring system. (ii) Total synthesis of tricyclic sesquiterpenoid albaflavenone using sequential intramolecular aldol condensations to construct its tricyclic framework. (iii) Total synthesis of paralemnolide A using an intramolecular Reformatsky-Honda reaction to construct the tricyclic framework. (iv) Synthetic study of marine diterpenoid aberrarone using a repeated 1,4-addition followed by intramolecular aldol reaction protocol to construct the tetracyclic framework.