Diastereoselective construction of a library of structural bispiro[butyrolactone/valerolactone–pyrrolidine–indanedione] hybrids via 1,3-dipolar cycloaddition reactions

Abstract

Herein, a highly efficient strategy that allows the diverse synthesis of a library of structural bispiro[butyrolactone–pyrrolidine–indanedione] hybrids is achieved effectively for the first time by means of 1,3-dipolar cycloadditions of α,β-unsaturated butyrolactones/valerolactones as dipolarophiles with azomethine ylides (thermally generated in situ from ninhydrin and proline or thioproline) via an exo′-transition state. Potentially bioactive target compounds have been obtained in good yields and diastereoselectivities (up to 89% yield and all cases >20 : 1 dr).