Two new initiators, namely, 4-(4-(2-(4-(allyloxy) phenyl)-5-hydroxypentane 2-yl) phenoxy)benzaldehyde and 4-(4-(allyloxy) phenyl)-4-(4-(4-formylphenoxy) phenyl) pentyl 2-bromo-2-methyl propanoate containing clickable hetero-functionalities namely aldehyde and allyloxy were synthesized starting from commercially available 4,4-bis(4-hydroxyphenyl) pentanoic acid. These initiators were utilized, respectively, for ring opening polymerization of epsilon-caprolactone and atom transfer radical polymerization of methyl methacrylate. Well-defined -aldehyde, -allyloxy heterobifunctionalized poly(epsilon-caprolactones) (Mn,GPC: 590029,000, PDI: 1.261.43) and poly(methyl methacrylate)s (Mn,GPC: 530028800, PDI: 1.191.25) were synthesized. The kinetic study of methyl methacrylate polymerization demonstrated controlled polymerization behavior. The presence of aldehyde and allyloxy functionality on polymers was confirmed by 1H NMR spectroscopy. Aldehyde-aminooxy and thiol-ene metal-free double click strategy was used to demonstrate reactivity of functional groups on polymers. (c) 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013, 51, 2091-2103