Influence of methoxy-and methyl-aromatic substituents on stereochemistry of the products in the acid-catalyzed cyclization of 2-(2-arylethyl)-1,3,3-trimethylcyclohexanols: stereocontrolled total synthesis of (±)-nimbidiol and (±)-nimbiol
作者:Bimal K. Banik、Sukumar Ghosh、Usha Ranjan Ghatak
DOI:10.1016/s0040-4020(01)86225-6
日期:1988.1
The distributions of the -and the -podocarpatrienes (-) and (-) in the cyclialkylation reaction of the easily accessible cyclohexanols (-) under a mild condition have been investigated. The cyclohexanol precursors having unactivated aromatic ring proceeds with high stereoselectivity leading to the respective -products, while the substrates with an electron donating methoxy or a methyl substituent with
的分布-和-podocarpatrienes(- )和(-在容易接近的环己醇的反应cyclialkylation()- )的温和条件下进行了研究。具有未活化的芳环的环己醇前体以高的立体选择性进行,从而产生相应的产物,而相对于亲电进攻位点具有给电子甲氧基或甲基取代基的底物则导致相应的-和-产品混合物。这些立体化学结果的一致机制已得到发展。基于这些结果,已经实现了改性的二萜(±)-亚氨基二醇(7)和(±)-亚氨基二醇甲醚(18)的简单合成。