Variable strategy toward carbasugars and relatives. 6. Diastereoselective synthesis of 2-deoxy-2-amino-5a-carba-beta-L-mannopyranuronic acid and 2-deoxy-2-amino-5a-carba-beta-L-mannopyranose.
Efficient, total syntheses of novel 2-deoxy-2-amino-5a-carba-beta-L-mannopyranuronic acid (1) and 2-deoxy-2-amino-5a-carba-beta-L-mannopyranose (2), a positional stereoisomer of validamine, have been achieved in 28% and 24% overall yields and in 12 steps and 13 steps, respectively, from 2-[(tert-butyldimethylsilyl)oxy]furan (3) and (2S)-2,3-O-isopropylideneglyceraldehyde N-benzyl imine (4) via two highly diastereoselective Mukaiyama aldol-related chemical maneuvers. The strategy, which furnishes the targeted carbasugars in enantiopure forms, allows for complete control of the configuration at all five contiguous stereocenters of the targets by utilizing the sole element of chirality present in the aldimine progenitor 4.
Istituto di Chimica Biomolecolare del CNR, Sezione di Sassari, Traversa La Crucca 3, I-07040 Li Punti, Sassari, Italy. giovanni.casiraghi@unipr.it
Gloria
G
Rassu
Luciana
L
Auzzas
Vincenzo
V
Zambrano
Paola
P
Burreddu
Luigi
L
Pinna
Lucia
L
Battistini
Franca
F
Zanardi
Giovanni
G
Casiraghi
D007294:Inositol / Q000031:analogs & derivatives* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009005:Monosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D014574:Uronic Acids / Q000138:chemical synthesis* / Q000737:chemistry
C484619:2-deoxy-2-amino-5a-carba-beta-L-mannopyranose; C484618:2-deoxy-2-amino-5a-carba-beta-L-mannopyranuronic acid; D009005:Monosaccharides; D014574:Uronic Acids; C042908:validamine; D007294:Inositol