Benzannulation via Ruthenium‐Catalyzed Diol—Diene [4 + 2] Cycloaddition: One‐ and Two‐Directional Syntheses of Fluoranthenes and Acenes.

A new benzannulation protocol is developed consisting of Ru-catalyzed diol-diene [4 + 2] cycloaddition and subsequent aromatization upon dehydration or deoxydehydration is developed to allow the synthesis of a diverse range of polycyclic arenes.