Kinetic aspects of the synthesis of (2-methacryloxy)ethyloxy functionalized poly(L-lactide) macromonomers using aluminum mono- and trialkoxides carrying this functionality are presented. The results show the living character of the ring-opening polymerization independently of the reaction temperature, but there are some deviations of the classical first order with respect to the monomer concentration, particularly at 60 degrees C and for low monomer/aluminum catalyst ratios. The comparative study of aluminum trialkoxides with respect to the corresponding monoalkoxides makes clear that the polymerization initiated by trialkoxides is at least five times faster than that initiated by the monoalkoxide. This behavior is explained by taking into consideration semiempirical calculations based on the PM-protocol, which gives an idea of the reactivity of mono- and trialkoxides with good agreement between theoretical and experimental results.