Chapter 3 Chemistry of the Diterpenoid Alkaloids

This chapter describes diterpenoid alkaloids as a group of highly oxygenated and complex natural compounds. They are divided into two broad categories, the norditerpenoid alkaloids based on a hexacyclic C19 skeleton and the diterpenoid alkaloids based on a number of C20 skeletons. The former is subdivided into four groups: the aconitine-type, lycoctonine-type, pyro-type, and lactone-type norditerpenoids. The diterpenoid alkaloids are also subdivided, mainly into three groups: the atisine, veatchine, and delnudine types. The term diterpenoid is occasionally used to cover both the C19 and C20 categories. The diterpenoid alkaloids have been studied for over 100 years. The chapter reviews the chemistry of diterpenoid alkaloids which lack explicit systematization according to reaction types. The chapter presents number of tables covering chemical reactions of diterpenoid alkaloids, showing the substrates, reaction conditions, products, yields, and key references. It discusses that yields are often the results of cursory observation; these tables are useful as a convenient point of departure for further studies on the chemistry of these alkaloids.