2-氯-2-氧代(硫代)-1,3,2-二氧磷杂环己烷的甲醇解及其开环异构化反应

Methanolysis and Ring - Opening Isomerization Reaction of 2 - Chloro- 4 - Phenyl -5,5- Dimethyl - 1,3,2- Dioxaphosphorinane 2 - Oxide(2 - Sulfide)

报道了trans-2-氧代-2-氯-4-苯基-5,5-二甲基-1,3,2-二氧磷杂环己烷以及cis-2-硫代-2-氯-4-苯基-5,5-二甲基-1,3,2-二氧磷杂环己烷甲醇解反应的立体化学.结果表明,反应体系的酸碱性对前者甲醇解反应的立体化学有着重要影响.而硫代环磷酰氯在磁性条件下的甲醇解反应存在一个开环异构化过程.

The stereochemistry of methanolysis reaction of trans - 2 - chloro - 4 - phenyl -5,5- dimethyl -1,3,2 - dioxaphosphorinane 2 - oxide (trans - 1) and CM - 2 - chloro - 4 - phenyl- 5,5 - dimethyl - 1,3,2 - dioxaphosphorinane 2 - sulfide (cis - 2) were described. Trans - 1 was treated with methanol to give inversion product at phosphorus. In contrast, retention is favored while the reaction employs methoxide ion as the nucleophile.Reaction of cis - 2 with sodium methoxide in methanol under reflux led to a ring opening followed by ring closure to give a thermodynamically controlled mixture of diastereomeric isomers in which trans isomer was the major component. An acyclic intermediate is found to be involved in this process.