Allylic Alcohols as Radical Allylating Agents. An Overall Olefination of Aldehydes and Ketones

2-Fluoropyridyl derivatives of allylic alcohols react with xanthates in the presence of lauroyl peroxide to give alkenes, often with high stereoselectivity. If the allylic alcohols are themselves derived from aldehydes or ketones, the overall process becomes a synthetic equivalent of the classical Wittig and related olefination reactions.