A direct approach to the synthesis of indolizidine and quinolizidine scaffolds of iminosugars is described. The presented strategy is based on a one-pot sugar lactam reduction with Schwartz’s reagent followed by a diastereoselective Mannich/Michael tandem reaction of the resulting sugar imine with Danishefsky’s diene. The stereochemical course of the investigated reaction has been explained in detail
First total synthesis of a new pyrrolizidine alkaloid, amphorogynine A
作者:Hidemi Yoda、Takahisa Egawa、Kunihiko Takabe
DOI:10.1016/s0040-4039(03)00070-4
日期:2003.2
An efficient and stereodefined strategy is described for the first asymmetric synthesis of a new type of pyrrolizidinealkaloids, amphorogynine A and its 1-epi-isomer. The key 2,4-disubstituted pyrrolidine ring was constructed by elaboration of the chiral lactam derivative incorporating the d-malic acid-derived skeleton through asymmetric cis-allylation of the functionalized allysilane.