A concise synthesis of castanospermine by the use of a transannular cyclization.
A nine-step synthesis of (+)-castanospermine has been accomplished in 22% overall yield from methyl alpha-D-glucopyranoside. The key transformations involve a zinc-mediated fragmentation of benzyl-protected methyl 6-iodoglucopyranoside, ring-closing olefin metathesis, and strain-release transannular cyclization to afford the indolizidine skeleton of the natural product.
Jensen
Thomas
T
Department of Chemistry, Building 201, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Mikkelsen
Mette
M
Lauritsen
Anne
A
Andresen
Thomas L
TL
Gotfredsen
Charlotte H
CH
Madsen
Robert
R
D003500:Cyclization; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism; D054836:Indolizidines
D007212:Indolizines; C037806:castanospermine; D054836:Indolizidines