ChemInform Abstract: Domino Double Michael—Claisen Cyclizations: A Powerful General Tool for Introducing Quaternary Stereocenters at C(4) of Cyclohexane‐1,3‐diones and Total Synthesis of Diverse Families of Sterically Congested Alkaloids.

Abstract

Cyclohexane derivatives Q 0040 Domino Double Michael-Claisen Cyclizations: A Powerful General Tool for Introducing Quaternary Stereocenters at C(4) of Cyclohexane-1,3-diones and TotalSynthesis of Diverse Families of Sterically Congested Alkaloids. -Treatment of ketones (I) and (X) with acrylate (II) allows a simple, concise, and efficient access to cyclohexadiones of type (III)/(XI) via double Michael addition and Claisen cyclization. These compounds are useful synthons which can smoothly be converted into diverse alkaloids like aspidospermidine (IX), mesembrine (XIII), and lycoramine (XIV). -(ISHIKAWA*, T.; KUDO, K.; KUROYABU, K.; UCHIDA, S.; KUDOH, T.; SAITO, S.; J.