Effect of solvent polarity extremes on the coupling of cyclopropylcarbene-chromium complexes and alkynes: Synthesis of β-alkoxycyclopentadienones, 2-cyclopentene-1,3-diones, and cis 4,5-disubstituted cyclopentenones

Article abstract of DOI:10.1016/S0040-4039(96)02282-4

The reaction between acetylenes and cyclopropylcarbene-chromium complexes in hexane affords exclusively cyclopentadienone derivatives in good yield, which are readily hydrolyzed to cyclopentenediones. The analogous reaction in 50:50 water dioxane affords cis disubstituted cyclopentenones.