Variable strategy toward carbasugars and relatives. 1. Stereocontrolled synthesis of pseudo-beta-D-gulopyranose, pseudo-beta-D-xylofuranose, (pseudo-beta-D-gulopyranosyl)amine, and (pseudo-beta-D-xylofuranosyl)amine.
Four novel, chiral nonracemic carbasugars have been synthesized from 1,2-O-isopropylidene-D-glyceraldehyde. Furan- and pyrrole-based 2-silyloxy dienes--mimics of the alpha,gamma-dianions of gamma-hydroxy- and gamma-aminobutanoic acid, respectively--nicely served to complete the syntheses of two all-oxygen compounds, pseudo-beta-D-gulopyranose and pseudo-beta-D-xylofuranose, and two "anomeric" amino derivatives, (pseudo-beta-D-gulopyranosyl)amine (1,2,4-tri-epi-validamine) and (pseudo-beta-D-xylofuranosyl)amine. Two sequential, highly diastereoselective carbon-carbon bond-forming maneuvers, i.e., a vinylogous crossed aldol addition and an intramolecular aldolization, proved central to these constructions. The fact that readily available heterocyclic diene scaffolds can be employed in the assembly of a varied repertoire of carbasugars and analogues widens the prospects of dienoxy silane chemistry.
Rassu
G
G
Istituto per l'Applicazione delle Tecniche Chimiche Avanzate ai Problemi Agrobiologici del CNR, Sassari, Italy.
Auzzas
L
L
Pinna
L
L
Battistini
L
L
Zanardi
F
F
Marzocchi
L
L
Acquotti
D
D
Casiraghi
G
G
D002241:Carbohydrates / Q000737:chemistry*; D003510:Cyclohexanes / Q000138:chemical synthesis*; D003517:Cyclopentanes / Q000138:chemical synthesis*; D005663:Furans / Q000737:chemistry; D008968:Molecular Conformation; D018716:Molecular Mimicry; D011758:Pyrroles / Q000737:chemistry; D013237:Stereoisomerism
D002241:Carbohydrates; D003510:Cyclohexanes; D003517:Cyclopentanes; D005663:Furans; D011758:Pyrroles