Reaction of F-alkanoic acid chlorides with trialkyl phosphites leading to 1-(dialkoxyphosphinyl)oxy-f-1-alkenephosphonates or 1-(dialkoxyphosphinyl)oxy-1H-F-alkanephosphonates☆

Abstract F -Alkanoic acid chlorides exothermically reacted with 2 equivalents of trialkyl phosphite without solvent at −20 °C to ambient temperature to give the corresponding dialkyl ( Z )-1- (dialkoxyphosphinyl)oxy- F -1-alkenephosphonate in high yields. When the reaction was conducted at −78 °C in an ethereal solvent, dialkyl 1-(dialkoxyphosphinyl)oxy-1 H - F -alkanephosphonate was obtained exclusively in place of the former alkenephosphonate. No F -acylphosphonate was detected in spite of the amount of the phosphite, the mode of addition, and the reaction temperature being varied.