Addition of 2-hydroxyethyl methacrylate upon 4,5- epoxy-4-methyloctane catalyzed by ceric ammonium nitrate 1: identification of the reaction products

Abstract

The alkoxylation of 4,5-epoxy-4-methyloctane, a model compound for epoxidized 1 ,4-polyisoprene, by 2-hydroxyethyl methacrylate (HEMA) in the presence of ceric ammonium nitrate (CAN) as catalyst was studied. The purpose was the identification and characterization of the reaction products formed during the addition of a photosensitive alcohol onto epoxidized 1,4-polyisoprene type structures, when the reaction is carried out in mild conditions. The products were characterized through NMR and FTIR spectroscopy, after fractionation by semi-preparative HPLC. Five main products were identified and characterized. Three of them result from the addition of the alcohol onto the epoxide (one saturated 1:1 adduct and two allylic 1:1 adducts). The other two are the result of epoxide rearrangements (a ketone and an allylic alcohol). The methacrylate photosensitive groups were recovered unchanged after the reaction.