Novel TSAO derivatives modified at positions 3 '' and 4 '' of the spiro moiety

We have explored the introduction of different functional groups at positio ns 3 " and 4 " of the spiro moiety of TSAO-T. Alkylation of this spiro moie ty afforded mixtures of N and/or C-alkylated derivatives, while acylation o ccurs, exclusively, on the amino group. Position 3 " has been selectively f unctionalized by halogenation followed by Stille-cross coupling reaction wi th organostannanes under a variety of experimental conditions.