Enantioselective total synthesis of otteliones A and B, novel and powerful antitumor agents from the freshwater plant Ottelia alismoides.

Otteliones A and B, isolated from the freshwater plant Ottelia alismoides, have attracted significant attention because of their potential as novel anticancer agents. In this review, four independent enantioselective total syntheses and one formal synthesis of these natural products are presented with particular focus on their methodology and strategy.