Enantioselective Diels-Alder Approach to C-3-Oxygenated Angucyclinones from (SS)-2-(p-Tolylsulfinyl)-1,4-naphthoquinone
作者:M. Carmen Carreño、Antonio Urbano、Claudio Di Vitta
DOI:10.1002/(sici)1521-3765(20000303)6:5<906::aid-chem906>3.0.co;2-g
日期:2000.3.3
quinones anti-6 and syn-7, which were obtained from the kinetic resolution of the racemic diene. In all cases, (SS)-(2-p-tolylsulfinyl)-1,4-naphthoquinone reacted from the less hindered face of the more reactive s-cis conformation, to form products in good enantiomeric excesses. Steric effects and torsional interactions in the corresponding approaches account for the observed pi-facial diastereoselectivities
在环己烯环的C-5位带有氧取代基和/或甲基的手性外消旋乙烯基环己烯2与对映体纯的(SS)-(2-p-甲苯基亚磺酰基)-1,4进行Diels-Alder反应-萘醌[(+)-1]。多米诺环加成/热解亚砜的消除过程导致形成对映异构体富集的角四环醌抗6和syn-7,这是由外消旋二烯的动力学拆分获得的。在所有情况下,(SS)-(2-对-甲苯基亚磺酰基)-1,4-萘醌从反应性更强的s-顺式构象的较少受阻面反应,形成对映体过量的产物。相应方法中的立体效应和扭转相互作用说明了在两个伙伴处观察到的pi面非对映选择性。