Organocatalytic Asymmetric Michael Addition of 2,2‐Dimethyl‐1,3‐dioxan‐5‐one to Nitro Alkenes Employing Proline‐Based Catalysts

Abstract

Abstract The organocatalytic asymmetric Michael addition of 2,2‐dimethyl‐1,3‐dioxan‐5‐one ( 1 ) was performed with various nitro alkenes 2 using a number of proline‐based catalysts ( A – M ) affording polyfunctional nitro ketones 3 . Reverse diastereoselectivity was observed with the diphenylprolinol catalyst J , and the best diastereo‐ and enantiomeric excesses were achieved with the sulfonamide catalyst M ( de = 84–98 %, ee = 81–86 %). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)