Hypervalent Iodine(III) promoted ring-rearrangement strategies in conformationally rigid ring systems

Abstract

The ring-rearrangement reactions are among the important class of atom economic chemical transformations as it involves direct construction of carbocylic or heterocyclic rings through bond migration reactions. The usefulness of such operation has been realized by many publications [1] and applications in the field of organic synthesis, medicinal chemistry, natural product synthesis and chemical biology [2]. Moreover, the inclusion of environmental benign hypervalent iodine(III) reagents in such processes allows to design a milder pathway to achieve desired ring-rearrangement reactions [3]. Herein, in the present context we have demonstrated a milder pathway for hypervalent iodine(III) mediated ring contraction of conformationally rigid exocyclic-β-enaminones for the synthesis of cyclopentanones with concurrent cyanation [4]. Furthermore, the synthesized cyclopentanones serves as a basic template for the synthesis of new class of ∂-valerolactams by the applications of hypervalent iodine reagents [5].