- A new synthetic entry to (-)-lasubineI and (+)-subcosineI has been established by employing the (S)-allylalkoxy benzylamine as a chiral synthon. The synthesis involves the formation of an α,β-unsaturated lactone by RCM reaction followed by an intramolecular Michael-type addition reaction as a key step, which enables the stereoselective construction of the cis-quinolizidine skeleton of lasubine
- 通过使用 (S)-烯丙基烷氧基苄胺作为手性合成子,建立了 (-)-lasubine I 和 (+)-subcosine I 的新合成条目。该合成涉及通过RCM反应形成α,β-不饱和内酯,然后是分子内迈克尔型加成反应作为关键步骤,这使得能够立体选择性地构建lasubine I和subcosine I的顺式-喹啉酮骨架。
Trifluoroacetyl-Activated Nitrogen−Nitrogen Bond Cleavage of Hydrazines by Samarium(II) Iodide
作者:Hui Ding、Gregory K. Friestad
DOI:10.1021/ol036480r
日期:2004.2.1
Trifluoroacetyl derivatives of hydrazines undergo clean and efficient reductive cleavage of the N-N bond with SmI2 in the presence of MeOH. After N-trifluoroacetylation, acyl-, aryl-, and alkyl-substituted hydrazines are reductively cleaved by this method to afford trifluoroacetamides in yields ranging from 70 to 96%. These conditions accommodate alkene functionality, avoid racemization, and furnish chiral amines bearing a readily removable TFA protecting group.