Studies on the intramolecular oxa-Pictet–Spengler rearrangement of 5-aryl-1,3-dioxolanes to 4-hydroxy-isochromans
作者:Darı́o A Bianchi、Federico Rúa、Teodoro S Kaufman
DOI:10.1016/j.tetlet.2003.10.143
日期:2004.1
3-disubstituted-4-hydroxy-isochromans, is influenced by the length and nature of the side chains bound to C-2 and C-4 of the dioxolane. Methyl groups yield a mixture of 4-hydroxy-isochromans in which the 1,3-trans diastereomer predominates, while bulkier substituents give 1,3-cis diastereomers. Functional groups in the C-2 side chain of the dioxolane ring may hinder cyclization by complexation with the promoter.
TiCl 4促进5-芳基-1,3-二氧戊环的oxa-Pictet-Spengler环化反应生成1,3-二取代-4-羟基-异色满的成功和立体化学结果受其长度和性质的影响。与二氧戊环的C-2和C-4结合的侧链。甲基产生4-羟基-异色满的混合物,其中1,3-反式非对映异构体占主导地位,而较大的取代基则形成1,3-顺式非对映异构体。二氧戊环环的C-2侧链中的官能团可能会因与启动子复合而阻碍环化作用。