Lomaiviticins A and B are complex antitumor antibiotics that were isolated from a strain of Micromonospora. A confluence of several unusual structural features renders the lomaiviticins exceedingly challenging targets for chemical synthesis. We report an 11-step, enantioselective synthetic route to lomaiviticin aglycon. Our route proceeds by late-stage, stereoselective dimerization of two equivalent monomeric intermediates, a transformation that may share parallels with the natural products' biosyntheses. The route we describe is scalable and convergent, and it lays the foundation for determination of the mode of action of these natural products.