Asymmetric Synthesis of the Epimeric (3S)-3-((E)-Hex-1-enyl)-2-methylcyclohexanones

Abstract

The asymmetric rhodium-catalysed 1,4-addition of alkenylzirconium reagents to 2-cyclohexenone can be useful in the synthesis of 3-alkenyl-2-methylcyclohexanones, provided that formaldehyde is used in trapping the intermediate zirconium enolates. In this manner a four-step sequence leading to the two epimeric 3-hexenyl-2-methylcyclohexanones in enantiomeric form was developed.

Keywords

• Enantioselective 1
• 4-addition
• zirconium O-enolate trapping
• 2-cyclo-hexenone.