Clarke Paul A, Zaytsev Andrey V, Morgan Tyson W, Whitwood Adrian C, Wilson Claire
Department of Chemistry, University of York, Heslington, York, North Yorks YO10 5DD, UK.
Org Lett. 2008 Jul 3;10(13):2877-80. doi: 10.1021/ol801051g. Epub 2008 Jun 6.
The one-pot synthesis of highly substituted piperid-4-ones has been achieved. Diketene is added to a tosyl imine in the presence of TiCl(4) and MeOH, followed by 1 equiv of aldehyde to generate 2,6-disubstituted nonsymmetrical piperid-4-ones as a mixture of cis-/trans-diastereomers in good yields. This mixture of diastereomers can be converted to a single 2,6- cis-diastereomer by epimerization with K(2)CO(3).
已实现了高取代哌啶 - 4 - 酮的一锅法合成。在TiCl(4)和甲醇存在下，将双乙烯酮加入到对甲苯磺酰亚胺中，然后加入1当量的醛，以良好的产率生成2,6 - 二取代的非对称哌啶 - 4 - 酮，为顺式/反式非对映异构体的混合物。通过用K(2)CO(3)进行差向异构化，这种非对映异构体混合物可以转化为单一的2,6 - 顺式非对映异构体。
