Total Synthesis of (±)-α-Acoradiene via Intramolecular Photoaddition and Reductive Cyclobutane Cleavage

(±)-α-Acoradiene (4) has been synthesized from 3-methoxy-2-cyclohexenone by a sequence of 8 steps. The key steps (Scheme 6) are the regio- and stereoselective photo[2+2]addition 7→6 and the reductive fragmentation 6→5 .