An efficient new method for the construction of vitaminD hydroxylated sidechains is described which is based on the alkylation and opening of epoxides by the ga-anions derived from nitriles 6 and 7.
A Synthetic Approach to the <i>Stemona</i> Alkaloids
作者:Mira M. Hinman、Clayton H. Heathcock
DOI:10.1021/jo0106391
日期:2001.11.1
This paper describes our work developing a strategy for the construction of the typical core structure of the Stemona alkaloids. The approach is to control the relative stereochemistry of the groups on the core 1-azabicyclo[5.3.0]decane ring system by a [3,3] sigmatropic rearrangement of an acylimmonium ion followed by selective reduction. After optimization, this reaction sequence afforded the desired