3,4,8,9-Tetramethyltetracyclo[4,4,0,03,9,04,8]decane-1,6-dioic anhydride. A photosensitized π2+πs2 intramolecular cycloaddition
Abstract
Photosensitized cycloaddition of the 1 : 2 Diels–Alder adduct of acetylene dicarboxylic acid and 2,3-dimethylbuta-1,3-diene affords (I) in 44% yield: this represents the simplest synthesis of this tetracyclo[4,4,0,03,9,04,8]decane ring system.