Synthesis of β-Amino and β-Methoxy Ketones by Lewis Acids Promoted β-Substitution Reactions of β,γ-Unsaturated Ketones

Abstract

A reaction mixture of β,γ-unsaturated ketone and BF₃·OEt₂ in CH₃OH was stirred at room temperature and β-methoxy ketone was produced in high yield. The β-amino ketone was obtained as the major product from a reaction mixture of β,γ-unsaturated ketone, AlCl₃ and Ts-NH₂ in CH₂Cl₂ at room temperature. This Lewis acid promoted β-substitution reaction mechanism was proposed as that the process occurred via in situ isomerization of β,γ-unsaturated ketone to α,β-unsaturated ketone followed by the 1,4-addition reaction.

Key words

β,γ-unsaturated ketone - β-amino ketone - β-methoxy ketone - α,β-unsaturated ketone - 1,4-addition reaction

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