Synthesis of Pyrrolidinols by Radical Additions to Carbonyls Groups

Francesca Marini,Martina Palomba,Luana Bagnoli,Claudio Santi

doi:10.3390/ecsoc-23-06606

Abstract

Radical cyclizations represent powerful synthetic strategies for the assembling of heterocycles. Most radical cyclizations are based on the addition to C C double or triple bonds. On the contrary, the addition to C O double bonds is rarely reported, since it proceeds reversibly due to the formation of thermodynamically unfavorable alkoxy radicals. Herein we report our attempts to construct substituted pyrrolidin-3-ols by tin-mediated radical cyclization of 5-phenylseleno-3-aza-pentanals. These rings are widely represented in natural products and drug candidates with various biological activities.

Highlights

Radical cyclizations are considered effective procedures for the assembling of five membered heterocycles [1,2] with useful applications in the stereoselective synthesis of natural and/or biologically active compounds
The cyclization occurs via an intramolecular addition of a carbon-centered radical to C C double bonds
A few years ago, we reported the stereoselective synthesis of tetrahydrofuran-3-ols by means of a tin-mediated radical cyclization of

Summary

Introduction

Radical cyclizations are considered effective procedures for the assembling of five membered heterocycles [1,2] with useful applications in the stereoselective synthesis of natural and/or biologically active compounds. The cyclization occurs via an intramolecular addition of a carbon-centered radical to C C double bonds. Scheme 1 shows examples of synthesis of tetrahydrofurans [5,6,7] and pyrrolidines [8,9,10] starting from 3-oxa or 3-aza-5-hexenyl radicals, via a 5-exo-trig cyclization paths. Examples of radical cyclization for the synthesis of tetrahydrofurans and pyrrolidines.

Results

Conclusion