???(CH2)nC(O)OR5, ???(CH2)nC(O)OR6, ???(CH2)nOR6, ???(CH2)nOC(O)R6, ???(CH2)nC(O)R6, and ???(CH2)nOC(O)OR6; wherein R5 is an acid labile group and R6 is selected from H, C1 to C6 linear, branched and cyclic alkyl, an epoxy containing group of structural formula II as defined above;