Concise Total Synthesis of Dihydrocorynanthenol, Protoemetinol, Protoemetine, 3‐epi‐Protoemetinol and Emetine

A concise asymmetric assembly of secologanine tryptamine and dopamine alkaloids by means of a one‐pot three‐component cascade reaction methodology is disclosed. This is demonstrated by the expeditious total syntheses of (–)‐dihydrocorynanthenol, (–)‐protoemetinol, (–)‐protoemetine, (–)‐3‐epi‐protoemetinol, and emetine (3–6 steps). The biomimetic synthetic strategy involved the following key steps: (i) One‐pot three‐component highly enantioselective catalytic Michael/Pictet–Spengler/lactamization cascade reactions; (ii) One‐pot tandem Swern oxidation/Wittig sequences; (iii) One‐pot tandem hydrogenation sequences.