An efficient eight-step assembly of the tetracyclic core (ABCD rings) of ent-(+)-nakadomarin A, a bioactive hexacyclic marine alkaloid, has been realized with Sonogashira coupling, platinum (II)-promoted cascade cyclizations, and saturation of a challenging carbon− carbon double bond through a hydroboration/oxidation/xanthate formation/Barton− McCombie deoxygenation sequence as key transformations.
