Amine-linked diglycosides: Synthesis facilitated by the enhanced reactivity of allylic electrophiles, and glycosidase inhibition assays

• Ian Cumpstey,
• Jens Frigell,
• Elias Pershagen,
• Tashfeen Akhtar,
• Elena Moreno-Clavijo,
• Inmaculada Robina,
• Dominic S. Alonzi and
• Terry D. Butters

Beilstein J. Org. Chem. 2011, 7, 1115–1123, doi:10.3762/bjoc.7.128

• electrophilicity at the allylic position, facilitating coupling reactions. Mitsunobu coupling between nosylamides and 2,3-unsaturated-4-alcohols gave the 4-amino-pseudodisaccharides with inversion of configuration as single regio- and diastereoisomers. A palladium-catalysed coupling between an amine and a 2,3

• -unsaturated 4-trichloroacetimidate gave a 2-amino-pseudodisaccharide as the major product, along with other minor products. Derivatisation of the C=C double bond in pseudodisaccharides allowed the formation of Man(N4–6)Glc and Man(N4–6)Man diglycosides. The amine-linked diglycosides were found to show weak

• glycosidase inhibitory activity. Keywords: amination; glycomimetics; glycosidases; Mitsunobu; pseudodisaccharides; Introduction We have been interested in synthesising molecules consisting of two monosaccharides linked by formal condensation without using the anomeric position [1]. Such molecules, termed

Carbasugar analogues of galactofuranosides: α-O-linked derivatives

• Jens Frigell and
• Ian Cumpstey

Beilstein J. Org. Chem. 2010, 6, 1127–1131, doi:10.3762/bjoc.6.129

• exemplify the method. Keywords: carbasugars; etherification; galactofuranose; glycomimetics; pseudodisaccharides; regioselective; Introduction Galactofuranose is found in nature as a component of glycoconjugates in many microorganisms [1][2]. Galactofuranosides with the α configuration are rather less

• electron-withdrawing group, the C3 benzyl ether. Ogawa has extensively used epoxide-opening reactions as a coupling method to access N- and O-linked pseudodisaccharides based on carbapyranoses [10]. The epoxides were opened by amines in uncatalysed reactions, or by alcohols under Lewis acidic, but more

• could offer a route to α-configured galactofuranoside pseudodisaccharides via a subsequent epimerisation of the unprotected C2 alcohol, analogous to the α-manno to α-gluco epimerisation route developed by Ogawa in the six-membered ring series [17]. In this paper we report our results on the synthesis of

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• solid-phase synthesis of cyclic trimers and tetramers containing pyranoid δ-SAAs. Synthesis of (thio)trehazoline, via triflate, from β-hydroxy(thio)urea. Retrosynthetic approach to synthesize thiourea-linked glycooligomers. Synthesis of guanidine-linked pseudodisaccharides via carbodiimide. Synthesis of