NOVEL INSERTION REACTIONS INTO CYCLIC TIN-OXYGEN COMPOUNDS

Article abstract of DOI:10.1016/S0022-328X(00)95255-0

A series of novel insertion reactions of cyclic carbonyl compounds into cyclic tin-oxygen compounds is described.Cyclic carboxycarbonate (1) and isatoic anhydride (4) react with cyclic stannoxane (2) to give the acyclic diester (3) and diamide (5) respectively.Cyclic anhydrides derived from aspartic and glutamic acids (6, 7, 10 and 11) react with 2 to give the macrocyclic tetralactones (8) and (9), and dilactones (12) and (13) respectively.These reactions may be of general synthetic value because of their high specificity.They lead either to singly acylated, acyclic products (3 and 5), or to regiospecific macrocyclic products (8, 9, 12 and 13) in preference to oligomers.The high specificity of these reactions is attributed to: (i) the dual function of the tin element, which may act either as activating group or as protecting group, and (ii) the occurrence of non-covalent transannular interactions between tin and oxygen in the cyclic stannoxane 2.