The reaction of β,γ−epoxy alcohols with titanium(III) reagents. A proposed role for intramolecular hydrogen bonding

β,γ-Epoxy alcohols are unique substrates for ring-opening reactions with titanium(III) reagents. The site selectivity of the initial radical-forming step as well as the nature and selectivity of reactions of the resultant carbon-centered radicals are often reversed from those observed for non-hydroxyl-containing epoxides. In this Report we critically review previous mechanistic proposals regarding these effects and propose an alternative explanation, which implicates intramolecular hydrogen bonding as a key control element.