Sensitized photocyclodimerization of αβ-unsaturated cyclic sulfones. Crystal structural analyses of the photodimers of 2-sulfolene and thia-2-cyclohexene-1,1-dioxide.
作者:Jochen Kuhn Hans、Rosalie Defoin、Klaus Gollnick、Carl Krüger、Tsay Yi-Hung、Liu Ling-Kang、Peter Betz
DOI:10.1016/s0040-4020(01)80031-4
日期:1989.1
The reactivity of five- and six-membered unsaturated cyclic sulfones in sensitized photocyclodimerization depends on position and substitution of the double bond. Thus, 2-sulfolene (1) and its six-membered analogue thia-2-cyclohexene-1,1-dioxide (3) photodimerize to yield each three products, 5, 6, 7 and 9, 10, 11, respectively, of which only 7 and 10 are analogous. However, 3-methyl-2-sulfolene (1a)
五元和六元不饱和环状砜在敏化光环二聚反应中的反应性取决于双键的位置和取代。因此,2环丁烯砜(1)和它的六元类似物硫杂-2-环己烯-1,1-二氧化物(3)photodimerize,得到每三个产品,5,6,7和9,10,11,分别其中只有7和10是相似的。但是,3-甲基-2-环丁烯(1a),3-环丁烯(2)及其3-甲基衍生物(2a)以及硫代-3-环己烯-1,1-二氧化物(4)在相同条件下保持不变。1和3的二聚也受到γ辐射的影响。通过晶体结构分析确定了六个二聚体的结构和立体化学。除了6,的γ辐射诱导的二聚化的主要产物1,所有其它的二聚体(5,7和9 - 11)是三环[2 + 2]与在中心环丁烷环的抗(transoid)构cycloadducts。图6是具有CC和CS键收缩的不饱和开链二聚体,后者表明双键与砜基团的共轭。而环丁烷环为5和7(从1开始)是平面的,所有3个从3开始的二聚体都折叠了;6