Efficient Synthesis and Subsequent Transformations of Phenylsulfanylbicyclo[2.2.2]octenones and Phenylselenylbicyclo[2.2.2]octenones
作者:Shih-Yu Gao、Santhosh Kumar Chittimalla、Gary Jing Chuang、Chun-Chen Liao
DOI:10.1021/jo802295p
日期:2009.2.20
sulfide and phenyl vinyl selenide furnished highly functionalized bicyclo[2.2.2]octenone derivatives 3 and 4, respectively, in excellent regio- and stereoselectivities and yields up to 90%. The bicyclo[2.2.2]octenone derivatives 3 with the sulfur functionality were subjected to an oxidation−elimination process to furnish bicyclo[2.2.2]octadienone systems 7 in good yields. During the reduction process,
掩蔽的邻苯并醌2与苯基乙烯基硫化物和苯基乙烯基硒化物的电子反Diels-Alder反应分别提供了高度官能化的双环[2.2.2]辛烯酮衍生物3和4,具有出色的区域选择性和立体选择性,产率最高90%。对具有硫官能度的双环[2.2.2]辛烯酮衍生物3进行氧化消除过程,以高收率提供双环[2.2.2]辛二烯酮体系7。在还原过程中,狄尔斯-阿尔德加合物3e和4e生成8,而其他加合物生成的以碳为中心的自由基图3a-d和图4a-d所提供的各种重排的产物9 - 13取决于所使用的(阮内镍或取代模式和试剂Ñ -Bu 3 SNH)。出乎意料的是,这些自由基显示出相对于烯属双键而言优选羰基官能度,从而导致了具有机械重要性和可能的合成实用性的有趣的重排反应。有趣的是,从Diels-Alder加合物3a-d还原获得的醇平稳地进行脱硫,从而以高收率得到脱硫产品。因此,“还原-脱硫-氧化”的de回方法提供了进入脱硫的双环[2