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。
Synthetic approaches to pentacyclic triterpenes of the arborane family II1 - @Tetracyclic intermediates
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.
Studies towards the total synthesis of pentacyclic triterpenes of the arborane and fernane family
作者:Simeon Arseniyadis、Ricardo Rodriguez、José Camara、Jean F. Gallard、Eric Guittet、Loïc Toupet、Guy Ourisson
DOI:10.1016/0040-4020(95)00530-l
日期:1995.1
Stereo and regrochemcal variations in conjugate addition reactions leading to isoarborinal and fernenol-Hke interpenes via a five-step protccol are described. The Gngnard addition on 9, 10, 15 and 18 served lo establish the relative stereoehemicul details.