Light-Induced Cycloaddition of 2,3-Dihydro-2,2-dimethyl-4H-thiopyran-4-one (a 4-Thiacyclohex-2-enone) to Alkenes and Dienes
作者:Kerstin Schmidt、Jürgen Kopf、Paul Margaretha
DOI:10.1002/hlca.200590147
日期:2005.7
The reactivity of (thiacyclic)-2,3-dihydro-2,2-dimethyl-4H-thiopyran-4-one (1a) in light-induced cycloadditions to furan (F), acrylonitrile (AN), or 2,3-dimethylbut-2-ene (TME) is compared to that of (carbocyclic) 5,5-dimethylcyclohex-2-enone (1b). Whereas for the more-flexible thiacycle, the efficiency of [2+2]-photocycloadduct formation with AN or TME is generally much lower, the diastereoselectivity
(硫代环)-2,3-二氢-2,2-二甲基-4 H-硫吡喃-4-酮(1a)在光诱导的环加成反应中与呋喃(F),丙烯腈(AN)或2,3的反应性将-二甲基丁-2-烯(TME)与(碳环的)5,5-二甲基环己-2-烯酮(1b)进行比较。对于更灵活的硫杂环戊烷,用AN或TME形成[2 + 2]-光环加合物的效率通常要低得多,而关于双环[4.2.0]辛烷中环稠合的非对映选择性对于两种烯酮而言都非常相似。相比之下,1a提供了带有F的完全反式融合的[4 + 2]环加合物,而1b主要给出相应的顺式融合产物。