3-SUBSTITUTED 2-CYCLOPENTENONES FROM CYCLOPENTADIENES

Abstract

Oxidation of cyclopentadienes 1a-1j, which were prepared by alkylation of cyclopentadienyl anion with the corresponding alkyl bromides, with pyridinium chlorochromate (PCC) gave the 2-cyclopentenones 2a-2j respectively in 10-15% yields. Reaction of 3 and 5 with PCC gave the spiro compounds 4 and 6 respectively in 75-80% yields.