Abstract
Intramolecular cycloadditions of arylketenes 4 proceed in excellent yield to give 5-arylbicy-clo[3.2.0]heptan-6-ones 5. Reaction of 5a with KOH in THF gives a 95:5 mixture of 7 and 10. Reaction of 5a with KOEt in ETOH give a 1:3 mixture of 7 and 10. Reaction of 5a with vinyllithium and treatment of the resulting alcohol 23 with KH gives the 1,3-sigmatropic rearrangement product 25.