Synthetic approaches to pentacyclic triterpenes of the arborane family II1 - @Tetracyclic intermediates
摘要:
Diels-Alder condensation of the bicyclic diene 1 with 2,6-dimethylbenzoquinone 2 under thermal and Lewis acid-catalyzed conditions gives the diastereomers 3, 4, 5 and 8; their structures are demonstrated by NMR analysis, in full agreement with the conformations deduced from molecular mechanics.
Regio- and stereochemical variations in Diels-Alder reactions
作者:Simeon Arseniyadis、Ricardo Rodriguez、Dmitry V. Yashunsky、José Camara、Guy Ourisson
DOI:10.1016/s0040-4039(00)76983-8
日期:1994.7
The AB+D ABCD approach for the synthesis of the tetracyclic intermediates 3–6 is reinvestigated. Water, high-pressure, LiCl and scandium triflate-mediated Diels-Alder reactions of 1 and 2 are reported.
重新研究了用于合成四环中间体3-6的AB + D ABCD方法。据报道,水,高压,LiCl和三氟甲磺酸scan介导的Diels-Alder反应为1和2。