Synthesis of Potassium (2R)‐2‐O‐α‐D‐Mannopyranosyl‐(1→2)‐α‐D‐glucopyranosyl‐2,3‐dihydroxypropanoate: A Naturally Compatible Solute

Abstract

Von der Fläche zum Raum: Komplexe dreieckige Anordnungen von Mn‐Ionen werden durch den Tripodliganden 1,1,1‐Tris(hydroxymethyl)ethan stabilisiert. Der selbstorganisierte abgestumpfte {Mn32}‐Würfel (siehe Bild) wird zudem durch end‐on‐verbrückende Azidliganden und Acetatgruppen stabilisiert. Diese Art der Stabilisierung könnte sich für die Herstellung von Einzelmolekülmagneten als nützlich erweisen.

Octanoylation of early intermediates of mycobacterial methylglucose lipopolysaccharides

“…These syntheses presented several challenges and our previous synthetic strategy of the related natural DGG [(2 R )-2- O -α- d -glucopyranosyl-(1→6)-α- d -glucopyranosyl-2,3-dihydroxypropanoate] required extensive modifications 36 . An additional ester, the 6-octanoate, needed to be introduced, and consequently the protecting group for the carboxylic acid of the glycerate moiety could not be a methyl ester as used previously 36 37 . Thus, the benzyl glycerate derivative 8 (benzyl (2R)-3- O - tert -butyldiphenylsilyl-2,3-dihydroxypropanoate; see Supplemental Information ) was synthesized and used in the synthesis of 1 and 2 , and the benzyl ester was easily removed in the final step by hydrogenation ( Fig.…”

“…Substrate specificity was assessed using glucose, mannose, galactose, sucrose (all from Sigma-Aldrich), laminaribiose (Dextra), trehalose, isomaltose maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose (Carbosynth), glucosamine, kanamycin and d,l -glyceric acid (sugars were all tested both independently and in combination with d,l -glyceric acid). GG (α- d -glucosyl-(1→2)- d -glycerate), GPG (α- d -glucosyl-3-phospho- d -glycerate), DGG (α- d -glucosyl-(1→6)-α- d -glucosyl-(1→2)- d -glycerate) 36 , MG (α- d -mannosyl-(1→2)- d -glycerate), MPG (α- d -mannosyl-3-phospho- d -glycerate) 73 , MGG (α- d -mannosyl-(1→2)-α- d -glucosyl-(1→2)- d -glycerate) were also tested as possible acceptors 37 . The CoA derivatives palmitoyl-CoA (C16), tetradecanoyl-CoA (C14), dodecanoyl-CoA (C12), decanoyl-CoA (C10), octanoyl-CoA (C8, Oct-CoA), hexanoyl-CoA (C6, Hex-CoA), succinyl-CoA, butyryl-CoA (C4), propionyl-CoA (C3) and acetyl-CoA (C2) (last three from Larodan Fine Chemicals) were tested as possible acyl donors.…”

Regioselective one-pot protection, protection–glycosylation and protection–glycosylation–glycosylation of carbohydrates: a case study withd-glucose

“…28 A synthetic approach to MMG was recently reported. 30 TMSOTf-catalysed protection to generate the glycosyl acceptor intermediate, followed by selective activation of the thiomannoside 22 gave the α1 → 2-linked disaccharide 23 as the glycosyl donor for further coupling. Finally, addition of the glycerate 31, 30 NIS, and TfOH to the reaction mixture delivered the desired MMG skeleton 32 in a one-pot yield of 34% (4 steps).…”

Immobilization of UDP‐Galactose on an Amphiphilic Resin

“…[18][19][20][21][22] Sugars are only coupled to resins through C6 when it is used as a synthetic aid and are detached before the end of the synthesis. [23][24][25] Conjugation of galactose to a resin through C6 is key not only to minimise interference with enzyme binding but also to allow addition of the nucleotide uridine to C1. Hence, immobilisation of UDP-galactose on a resin presented the following challenges: selective addition of the linker at the C6 position for subsequent coupling to the resin; the sensitivity of the phosphate to acidic conditions; selective fluorination at C4; the low reaction rates of uridine morpholidate with galactose phosphate.…”

“…Most sugars are attached to solid‐phase supports or resins through C1 with no nucleotide present . Sugars are only coupled to resins through C6 when it is used as a synthetic aid and are detached before the end of the synthesis . Conjugation of galactose to a resin through C6 is key not only to minimise interference with enzyme binding but also to allow addition of the nucleotide uridine to C1.…”