The synthesis of new octafunctional alkoxyamine initiators for nitroxide-mediated radical polymerization (NMRP), by the derivatization of resorcinarene with nitroxide free radicals viz TEMPO and a freshly prepared phosphonylated nitroxide, is described. The efficiency of these initiators toward the controlled radical polymerization of styrene and tert-butyl acrylate is investigated in detail. Linear analogues of these multifunctional initiators were also prepared to compare and evaluate their initiation efficiency. The favorable conditions for polymerization were optimized by varying the concentration of initiators and free nitroxides, reaction conditions, etc., to obtain well-defined star polymers. Star polystyrene thus obtained were further used as macro-initiator for the block copolymerization with tert-butyl acrylate. (c) 2007 Wiley Periodicals, Inc.