Total Syntheses of (−)-Methyl Atis-16-en-19-oate, (−)-Methyl Kaur-16-en-19-oate, and (−)-Methyl Trachyloban-19-oate by a Combination of Palladium-Catalyzed Cycloalkenylation and Homoallyl−Homoallyl Radical Rearrangement
作者:Masahiro Toyota、Toshihiro Wada、Masataka Ihara
DOI:10.1021/jo000142b
日期:2000.7.1
Asymmetric total syntheses of (-)-methyl atis-16-en-19-oate (1c), (-)-methyl kaur-16-en-19-oate (2c), and (-)-methyl trachyloban-19-oate (3c) have been achieved by employing a hybrid strategy of palladium-catalyzed cycloalkenylation and homoallyl-homoallyl radical rearrangement. The common synthetic intermediate 5 was prepared from 2-allylcyclohexanone (4) with 98% ee using d'Angelo's asymmetric Michael
(-)-甲基atis-16-en-19-oate(1c),(-甲基kaur-16-en-19-oate(2c)和(-)-甲基trachyloban-19-通过使用钯催化的环烯基化和均烯丙基-均烯丙基芳基重排的混合策略已经获得了酸酯(3c)。使用d'Angelo's不对称迈克尔加成法,由具有98%ee的2-烯丙基环己酮(4)制备常见的合成中间体5。通过钯催化的环烯基化反应,在5个官能团上进行的一系列修饰导致生成(+)-14,这是我们已经作为外消旋体制备的。(-)-atis-16-ene-19-oate(1c)通过均烯丙基-均烯丙基自由基重排生成。另一方面,Wolff-Kishner还原18,然后进行酯化反应生成(-)-甲基kaur-16-en-19-酸酯(2c)和(-)-甲基Trachyloban-19-酸酯(3c)。