α-Iodo enol ethers, precursors of acyl anion equivalents, are not easily prepared. Herein we report that addition of activated iodoalkanes to ynol ethers under mild and neutral radical reaction conditions leads to α-iodo enol ethers in moderate to excellent yields with high stereoselectivity. The reaction can be carried out in various solvents at different temperatures. The methodology allows the preparation of β-alkylated and β,β-dialkylated α-iodo enol ethers. Reduction of the carbon-iodine bond of these species leads to the corresponding enol ethers with good yields.Key words: ynol ethers, enol ethers, radical addition, stereoselective.
作为酰基阴离子等价物的前体,α-碘烯醇醚的制备并不容易。我们在此报告,在温和的中性自由基反应条件下,将活化的碘烷烃加到炔醇醚中,可得到中等到极好收率的α-碘烯醇醚,并且具有很高的立体选择性。该反应可在不同温度、不同溶剂中进行。该方法可制备 β-烷基化和 β,β-二烷基化的 α-碘烯醇醚。通过还原这些物质的碳-碘键,可以得到相应的烯醇醚,而且产率很高。