Elimination versus Ring Opening: A Convergent Route to Allrylidene-Cyclobutanes

Functionalized alkylidene-cyclobutanes have been prepared from 2-fluoropyridinyl-6-oxy precursors derived from vinyl cyclobutanols by a radical addition elimination process. A wide range of functional groups is tolerated, and the alkylidene-cyclobutanes can be further elaborated Into cyclopentanones. The limitation of this approach resides in the competition with opening of the cyclobutane ring.