JOURNAL OF ORGANIC CHEMISTRY, vol.59, no.4, pp.699-701, 1994 (SCI-Expanded)
Reaction of chromium carbene complexes and 1-alkynylcyclobutenols leads to 2-alkenyl-4-cyclopentene-1,3-diones. Initial allkyne insertion affords a highly electrophilic carbene complex, which then undergoes an alkyl shift-ring expansion, ultimately producing 2-alkenyl-4-cyclopentene-1,3-diones.