Intermolecular hydrogen-atom abstraction by vinyl radicals derived from hydroxyalkyl radicals and alkynes: an electron spin resonance investigation

Abstract

The rapid addition of α-hydroxyalkyl radicals ˙CR¹R²OH (R¹= H, Me; R²= H, Me) to butynedioic acid to give intermediate vinyl radicals (k ca. 10⁷ dm³ mol^–1 s^–1) is followed by intermolecular hydrogen-transfer (k ca. 10⁶ dm³ mol^–1 s^–1) from the parent alkanols. The alkenes thus formed also undergo subsequent ready addition of ˙CR¹R²OH to give radicals which in some cases demonstrate unusual line-broadening effects.