Abstract The effects on the rates of cleavage of 3-ClC 6 H 4 CH 2 MMe 3 and 3, 5-Cl 2 C 6 H 3 CH 2 MMe 3 compounds with M= Si and Sn have been examined for (a) various concentrations of NaOMe-MeOH;(b) various concentrations of H 2 O in NaOHH 2 O-eOH; and (c) variation of R from Me to Et, i-Pr and t-Bu for metal alkoxide-ROH mixtures. Rates have also been measured for cleavages in NaOCH 2 CF 3 HOCH 2 CF 3-Me 2 SO. In all ...