Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada V8W 3V6.
J Org Chem. 2012 Oct 5;77(19):8634-47. doi: 10.1021/jo301565u. Epub 2012 Sep 21.
We recently described an iterative synthesis of oligo-vinyl ethers, followed by a radical cascade to provide a family of hexahydro-2H-furo[3,4-b]pyrans. Our results for the radical cascade were consistent with either a direct 6-endo-trig addition of a vinyl radical onto the first vinyl ether function or an initial 5-exo-trig addition, followed by rearrangement to the more stable anomeric radical intermediate. In this report, we describe our further mechanistic studies aimed at distinguishing between these two possibilities and conclude that the 5-exo/3-exo/retro-3-exo pathway is dominant.
我们最近描述了一种寡聚乙烯基醚的迭代合成方法，然后通过自由基级联反应得到了一系列六氢-2H-呋喃并[3,4-b]吡喃。我们的自由基级联反应结果与乙烯基自由基直接在第一个乙烯基醚官能团上进行 6-endo-trig 加成或初始 5-exo-trig 加成，然后重排至更稳定的端基自由基中间体一致。在本报告中，我们描述了进一步的机理研究，旨在区分这两种可能性，并得出结论，5-exo/3-exo/retro-3-exo 途径占主导地位。
