Stereoselective synthesis of (R)-(+)-1-methoxyspirobrassinin, (2R,3R)-(−)-1-methoxyspirobrassinol methyl ether and their enantiomers or diastereoisomers
作者:Zuzana Čurillová、Peter Kutschy、Mariana Budovská、Atsufumi Nakahashi、Kenji Monde
DOI:10.1016/j.tetlet.2007.09.080
日期:2007.11
phytoalexin (R)-(+)-1-methoxyspirobrassinin and its unnatural (S)-(−)-enantiomer was achieved by spirocyclization of 1-methoxybrassinin in the presence of (+)- and (−)-menthol and subsequent oxidation of the obtained menthyl ethers. Methanolysis of menthyl ethers in the presence of TFA afforded (2R,3R)-(−)-1-methoxyspirobrassinol methyl ether as well its unnatural (2S,3S)-, (2R,3S)-, and (2S,3R)-isomers
(十字花科吲哚植物抗毒素的立体选择性合成- [R(+) - - )1-methoxyspirobrassinin和其非天然(小号) - ( - ) -对映异构体通过在(+)的存在下1- methoxybrassinin的螺环化来实现-和( - ) -薄荷醇和随后氧化得到的薄荷醚。在TFA存在下,对薄荷基醚进行甲醇分解,得到(2 R,3 R)-(-)-1-甲氧基螺spir菜油醇甲基醚及其非天然的(2 S,3 S)-,(2 R,3 S)-和(2 S,3 R)-异构体。