Reactivity of β - Stannylketones . Elimination vs . Substitution

In the present work we report the results obtained in the reaction of βstannylketones (I) with t-BuONa in dimethylsulfoxide (DMSO) and acetonitrile (ACN) as solvents. The reaction mechanisms probably involved are proposed. Introduction In the reaction of β-functionalized organotin compounds (I) with t-BuONa in t-BuOH there is a competition between an elimination reaction [(E1cB)R], leading to olefins with high diastereoselectivity, and a nucleofilic substitution reaction yielding the reduction product (II) [1]. Now we report on the reactions of β-stannylketones (I) with t-BuONa in DMSO and ACN in order to compare the reactivity in these solvents. Experimental Anhydrous solvents and sublimated t-BuONa were used. The β-stannylketones were synthesized in our laboratory [2-3]. The reaction mixtures were analysed by CGL. The reaction conditions are detailed in the Table. Sn Z Ph R BuONa DMSO or ACN H Z R Ph