An Unexpected Thermal [1,3]-[1,3]-<i>para</i>Rearrangement of Chromone-3-ylmethyl Aryl Ethers: Mechanism and Application of the Intercepted [1,3]-Rearranged Intermediates to the Synthesis of<i>cis</i>-Homopterocarpans
作者:Krishnan Devarajan、Somasundaram Devaraj、Kalpattu K Balasubramanian、Shanmugasundaram Bhagavathy
DOI:10.1246/cl.141162
日期:2015.4.5
Chromone-3-ylmethyl aryl ethers with unsubstituted ortho-positions have been found to undergo a novel domino [1,3]-[1,3]-rearrangement to give 4′-hydroxyhomoisoflavones under thermal conditions while the para-substituted ethers lead to 2′-hydroxyhomoisoflavones involving an O- to C-[1,3]-migration, instead of the expected Claisen rearrangement. A few cis-homopterocarpans have been synthesized using the 2′-hydroxyhomoisoflavones obtained from the thermal [1,3]-rearrangement of chromene-3-ylmethyl aryl ethers.
发现未取代的邻位的色酮-3-基甲基芳基醚在热条件下发生一种新颖的多米诺[1,3]-[1,3]-重排反应,生成4′-羟基同异黄酮,而对位取代的醚则导致2′-羟基同异黄酮的形成,涉及O到C的[1,3]-迁移,而不是预期的克莱森重排反应。使用从色烯-3-基甲基芳基醚的热[1,3]-重排中获得的2′-羟基同异黄酮合成了一些顺式同异托烯类化合物。