Diastereo- and Enantioselective Synthesis of 4-Nitrocyclohexanones by [4+2] Cycloaddition of a Chiral 2-Aminobutadiene to Nitroalkenes

Abstract

The Diels-Alder reaction of 3-[(S)-2-(methoxymethyl)pyrrolidin-1-yl]-1,3-butadiene [(S)-3] with 2-aryl-1-nitroethenes afforded, after hydrolysis, the 5-aryl-2-methyl substituted 4-nitrocyclohexanones (R,S,R)-5 in excellent enantiomeric purities (ee = 95-99 %) and with high diastereoselectivities (ds = 75-95 %).