Stereospecific and Stereoselective Rhodium(I)‐Catalyzed Intramolecular [2+2+2] Cycloaddition of Allene‐Ene‐Ynes: Construction of Bicyclo[4.1.0]heptenes

Treatment of the allene-ene-yne substrates with [{RhCl(CO)2}2] effected the intramolecular [2+2+2]-type ring-closing reaction to produce various of tri- and tetracyclic derivatives containing a cyclopropane ring. The reaction is highly stereoselective as well as stereospecific with good to excellent yields.