High Pressure-Promoted [2+2] Cycloaddition Reactions of 4-Methylphenyl 1,2-Propadienyl Sulfone with Enol Ethers
作者:René W. M. Aben、Samuel Braverman、Hans W. Scheeren
DOI:10.1002/ejoc.200390135
日期:2003.3
Under high pressure conditions, 4-methylphenyl 1,2-propadienyl sulfone (1) and enol ethers (6) undergo regioselective [2+2] cycloaddition reactions to give (3-alkoxycyclobutylidene)methyl 4-methylphenyl sulfones (7). The cycloaddition reaction has a broad scope with respect to the substituents allowed at the enol ether. The synthetic potential of the obtained cycloadducts is illustrated by a stereoselective
在高压条件下,4-甲基苯基 1,2-丙二烯基砜 (1) 和烯醇醚 (6) 进行区域选择性 [2+2] 环加成反应,得到 (3-烷氧基亚环丁基) 甲基 4-甲基苯基砜 (7)。环加成反应在烯醇醚上允许的取代基方面具有广泛的范围。所得环加合物的合成潜力通过将二甲胺立体选择性加成到 7a 和 7b 的双键上得到 11a 和 11b 以及叔胺诱导的 7a 和 7b 的双键异构化,然后开环来说明环丁烯中间体生成 1-烷氧基丁-1,3-二烯 12a 和 12b。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)