Polyether dendrons have been successfully used as macroinitiators for the living ring-opening polymerization (ROP) of lactones and lactides. A hydroxyl group located at the focal point of dendrimers of different generations was transformed into diethyl aluminum alkoxides by reaction with triethyl aluminum. The dendritic aluminum alkoxides proved to be efficient macroinitiators for the living ROP of epsilon-caprolactone (epsilon CL), 1,4,8-trioxa(4,6)spiro [9]undecanone (TOSUO), D,L- and L,L-lactide. Formation of these block copolymers of unusual macromolecular architecture was supported by size exclusion chromatography and spectroscopy. The versatility of this synthetic approach allowed omega-functional dendrimer bloch-polyesters, such as macromonomer, and macromolecules with novel architectures, to be prepared.