Hydrolysis of α-alkyl-α-(methylthio) methylene meldrum's acids. A kinetic and computational investigation of steric effects

…, M Ali, Z Rappoport, H Yamataka, H Salim

Index: Bernasconi, Claude F.; Brown, Shoshana D.; Ali, Mahammad; Rappoport, Zvi; Yamataka, Hiroshi; Salim, Hatim Journal of Organic Chemistry, 2006 , vol. 71, # 13 p. 4795 - 4802

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Citation Number: 12

Abstract

The rates of hydrolysis of α-R-α-(methylthio) methylene Meldrum's acids (8-R with R= H, Me, Et, s-Bu, and t-Bu) were determined in basic and acidic solution in 50% DMSO-50% water (v/v) at 20° C. In basic solution (KOH), nucleophilic attack to form a tetrahedral intermediate () is rate limiting for all substrates (k 1OH). In acidic solution (HCl) and at intermediate pH values (acetate buffers), water attack (k 1H2O) is rate limiting for 8-Me, 8-Et, and 8-s-Bu; ...