332178-31-1Relevant articles and documents
A short synthetic route to the calystegine alkaloids
Skaanderup, Philip R.,Madsen, Robert
, p. 2115 - 2122 (2007/10/03)
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 1,8-nonadienes, thus formed, are converted into cycloheptenes by ring-closing olefin metathesis. Regioselective hydroboration and oxidation give the corresponding cycloheptanones, which are deprotected to afford the desired calystegines. Hereby, calystegine B2, B3, and B4 are prepared from D-glucose, D-galactose, and D-mannose, respectively. This route constitutes the shortest synthesis of calystegine B2 and gives rise to the first total syntheses of calystegine B3 and B4.
A short and efficient synthesis of (+)-calystegine B2
Boyer, Fran?ois-Didier,Hanna, Issam
, p. 1275 - 1277 (2007/10/03)
A short synthesis of (+)-calystegine B2 from (D)-glucose has been achieved, which involves as the key step a triple domino zinc-mediated reductive ring-opening, imine formation and allylation reaction of 6-iodoglucopyranose.