Reaction of 1-methylcyclopropene with ketens. A ready ene reaction and evidence for unstable enol and cyclopropanone intermediates
Abstract
The addition of t-butylcyanoketen and bis(trifluoromethyl)keten to 1-methylcyclopropene gives mixtures of ene products and rearranged products (5) and (12) from competing stepwise pathways via dipolar ions (9) and (14) and a cyclopropanone (15).