C. Vogel et al., GALACTURONIC ACID-DERIVATIVES .8. SYNTHESIS OF N-(D-GALACTURONOYL) AMINO-ACIDS AND DIPEPTIDES, Liebigs Annalen, (4), 1997, pp. 737-743
D-Galacturonic acid derivatives, amide-linked to amino acids or dipept
ides, have been synthesized. These glycoconjugates exhibit stability w
hen the uronic acid residue is protected with isopropylidene and acety
l groups or is in its pyranoside form. The formation of the amide or p
eptide linkages was best achieved by the EDCI/HOBt coupling method; an
alternative method employing the 4-di-O-isopropylidene-alpha-D-galact
opyranuronosyl chloride 2 furnished only moderate yields of the conjug
ates. The use of NMR spectroscopy to detect racemization of the amino
acid moiety is also discussed herein.