A Short Synthetic Route to the Calystegine Alkaloids
作者:Philip R. Skaanderup、Robert Madsen
DOI:10.1021/jo020645c
日期:2003.3.1
An efficient strategy is described for the synthesis of enantiopure calystegine alkaloids. The key step employs a zinc-mediated fragmentation of benzyl-protected methyl 6-iodo-glycosides followed by in situ formation of the benzyl imine and Barbier-type allylation with zinc, magnesium, or indium metal. Stereochemistry in the pivotal allylation is controlled by the choice of the metal. The functionalized
Short syntheses of enantiopure calystegine B2, B3, and B4
作者:Philip R. Skaanderup、Robert Madsen
DOI:10.1039/b102353p
日期:——
Calystegine B2, B3, and B4 have been prepared in 5 steps from the benzyl protected methyl 6-iodoglycopyranosides of glucose, galactose and mannose, respectively, by using a zinc-mediated domino reaction followed by ring-closing olefin metathesis as the key steps.