Title: Total Synthesis of (−)-Nakadomarin A.
Description: A convergent and scalable total synthesis of polycyclic manzamine alkaloid (-)-nakadomarin A is described. Unsaturated bicyclic lactam fragment A was prepared from acrolein in 5 steps, and macrolactam fragment B was prepared from 3-furfural in 7 steps. A double Michael addition reaction (or cyclization) between A and B provided the desired fragment coupling product C in 79% yield and 9:1 dr on more than one-gram scale. Completion of the total synthesis of (-)-nakadomarin A was then achieved in a one-pot transformation from compound C.