Spirocyclic phenoxides of germanium, zirconium, and tin were prepared from 2,2 '-dihydroxybiphenyl and 2,2 '-dihydroxy-1,1 '-binaphthyl. Ring-expansion polymerizations of l-lactide are mainly studied at 160 or 180 degrees C. The reactivity of the catalysts increases in the order: Zr < Ge < Sn. Regardless of catalyst, the weight-average molecular weights (M-w) never exceed 50,000 g mol(-1). The resulting poly(l-lactide)s are optically pure and have a cyclic architecture. Decreasing temperature and time favor formation of even-numbered cycles, and at 102 degrees cyclics, almost free of odd-numbered rings are obtained. Analogous polymerizations of meso-lactide give similar results >120 degrees C, but different results at 100 or 80 degrees C. Surprisingly, bell-shaped narrow molecular weight distributions are obtained <140 degrees C, resembling the pattern of living polymerizations found for alcohol-initiated polymerizations. An unusual transesterification mechanism yielding narrow distributions of odd-numbered cycles is discovered too. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2730-2738