Transesterification processes for producing a compound of formula (I) wherein R1 is H or a methyl group, A and B are each, independently, a linear or branched C2-C5 alkylene group, comprising reacting: an acrylate or methacrylate of formula (II) wherein R1 is H or a methyl group and R2 is a C1-C4 alkyl group, with a compound of formula (III) wherein the reaction is performed: (i) in the presence of calcium oxide and calcium hydroxide, and (ii) wherein the molar ratio of the compounds of formula (II) to formula (III) is less than 4:1 or 3:1 respectively.