Contrasting conformational behavior of 5-methylsulfonyl-1,3-dioxane and -1,3-dithiane in the minimization of steric and electrostatic repulsive interactions
作者:J.Samuel Cruz-Sánchez、Eusebio Juaristi
DOI:10.1016/s0040-4039(02)02308-0
日期:2002.12
The preparation of novel 1,3-dithiane derivatives, cis- and trans-2-tert-butyl-5-methylsulfonyl-1,3-dithiane, was achieved by acid-catalyzed condensation of 2-methylsulfonyl-1,3-propanedithiol with pivalaldehyde. The former dithiol was obtained from allylmethylsulfide via the Knochel–Normant bromination–rearrangement protocol. Configurational and conformational assignment of cis- and trans-5 was based
通过酸催化2-甲基磺酰基-1,3-丙二硫醇与苯甲酸的缩合反应,可以制备新型的1,3-二硫杂环丁烷衍生物顺式和反式-2-叔丁基-5-甲基磺酰基-1,3-二硫醚。新戊醛。前者的二硫醇是通过Knochel-Normant溴化-重排方案从烯丙基甲基硫获得的。的构型和构象分配顺-和反式- 5是根据1点H NMR分析,并且发现该反式异构体采用常规椅式构象。相比之下,顺式- 5为了使轴向甲基磺酰基产生的空间和静电排斥相互作用减至最小,采用扭曲结构。化学平衡顺- 5 ⇌ TRAN S- 5示出了后者由1.50至更加稳定千卡/摩尔。