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

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 alpha,beta-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).

Automated summary

A highly efficient strategy for the diverse synthesis of structural bispiro[butyrolactone-pyrrolidine-indanedione] hybrids is achieved for the first time using 1,3-dipolar cycloadditions. The strategy involves the reaction between α,β-unsaturated butyrolactones/valerolactones and azomethine ylides, which are generated in situ from ninhydrin and proline or thioproline. The target compounds, with potential bioactivity, are obtained in good yields and diastereoselectivities.