Cascade radical cyclisations of methylenecyclopropyl ketones—synthesis of bicyclo-[3.2.1]-octanes
作者:Alexandre C. Saint-Dizier、Jeremy D. Kilburn
DOI:10.1016/s0040-4039(02)01329-1
日期:2002.8
Samarium diiodide mediated cyclisation of methylenecyclopropyl ketones, readily prepared from β-ketoesters provides a simple route to bicyclo-[3.2.1]-octanes.
The asymmetric synthesis of cyclopentane derivatives by palladium-catalyzed coupling of prochiral alkylboron compounds
作者:Suk Young Cho、Masakatsu Shibasaki
DOI:10.1016/s0957-4166(98)00386-3
日期:1998.11
Treatment of the prochiral triflate 2a with Pd-2(dba)(3). CHCl3, (S)-(R)-BPPFOAc and K2CO3, in THF at 40 degrees C, gave the cyclopentane derivative 10 in 58% yield and in 28% ee after oxidative work-up and benzoylation. Moreover, reaction of the prochiral triflate 2c with Pd-2(dba)(3). CHCl3, (S)-(R)-PPFA and K2CO3, in THF at 40 degrees C, afforded the cyclopentane derivative 3b, with a quaternary carbon center, in 42% yield and in 31% ee after oxidative work-up. (C) 1998 Elsevier Science Ltd. All rights reserved.