Highly diastereoselective formation of 3,7-dioxabicyclo[3.3.0]octan-2-ones in reaction of 2-arylcyclopropanedicarboxylates with aromatic aldehydes using 1,2-zwitterionic reactivity type
作者:Denis D. Borisov、Roman A. Novikov、Yury V. Tomilov
DOI:10.1016/j.tetlet.2017.08.025
日期:2017.9
A new reaction of 2-arylcyclopropane-1,1-dicarboxylates (ACDC) with aromatic aldehydes that occurs via generation of a 1,2-zwitterionic intermediate in the presence of GaCl3 has been developed. This process results in the 3,7-dioxabicyclo[3.3.0]octane frame by addition of two aldehyde molecules to an ACDC molecule. The reaction is a complex anionic-cationic cascade process involving the formation of
已经开发了2-芳基环丙烷-1,1-二羧酸酯(ACDC)与芳族醛的新反应,该反应通过在GaCl 3存在下生成1,2-两性离子中间体而发生。该过程通过将两个醛分子加到ACDC分子上而形成3,7-二氧杂双环[3.3.0]辛烷构架。该反应是一个复杂的阴离子-阳离子级联过程,涉及形成两个C–C键,两个C–O键和五个立体中心。该过程以高非对映选择性发生,仅产生一种非对映异构体。提出了一种可能的反应机理,并由NMR监测数据证实。