Stannyl ceramides as efficient acceptors for synthesising β-galactosyl ceramides

Morales‐Serna, José Antonio; Dı́az, Yolanda; Matheu, M. Isabel; Castillón, Sergio

doi:10.1039/b809570a

Cited by 10 publications

(9 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This methodology nicely complements reactions of per- O -acetylated lactose, which afford the β-anomer due to neighboring group participation of the C-2 acetate. 52 …”

Section: Resultsmentioning

confidence: 99%

Integrating ReSET with Glycosyl Iodide Glycosylation in Step-Economy Syntheses of Tumor-Associated Carbohydrate Antigens and Immunogenic Glycolipids

2014

View full text Add to dashboard Cite

Carbohydrates mediate a wide range of biological processes, and understanding these events and how they might be influenced is a complex undertaking that requires access to pure glycoconjugates. The isolation of sufficient quantities of carbohydrates and glycolipids from biological samples remains a significant challenge that has redirected efforts toward chemical synthesis. However, progress toward complex glycoconjugate total synthesis has been slowed by the need for multiple protection and deprotection steps owing to the large number of similarly reactive hydroxyls in carbohydrates. Two methodologies, regioselective silyl exchange technology (ReSET) and glycosyl iodide glycosylation have now been integrated to streamline the synthesis of the globo series trisaccharides (globotriaose and isoglobotriaose) and α-lactosylceramide (α-LacCer). These glycoconjugates include tumor-associated carbohydrate antigens (TACAs) and immunostimulatory glycolipids that hold promise as immunotherapeutics. Beyond the utility of the step-economy syntheses afforded by this synthetic platform, the studies also reveal a unique electronic interplay between acetate and silyl ether protecting groups. Incorporation of acetates proximal to silyl ethers attenuates their reactivity while reducing undesirable side reactions. This phenomenon can be used to fine-tune the reactivity of silylated/acetylated sugar building blocks.

show abstract

“…This methodology nicely complements reactions of per- O -acetylated lactose, which afford the β-anomer due to neighboring group participation of the C-2 acetate. 52 …”

Section: Resultsmentioning

confidence: 99%

Integrating ReSET with Glycosyl Iodide Glycosylation in Step-Economy Syntheses of Tumor-Associated Carbohydrate Antigens and Immunogenic Glycolipids

2014

View full text Add to dashboard Cite

show abstract

“…273,274 Disarmed glycosyl donor−promoter pairs provided excellent yields and stereoselectivity when glycosylated with a broad range of stannylated glycosyl acceptors. 274 Recently, D'Angelo and Taylor developed a concise, convergent route to glycosyl ceramides using diphenylboronic acid-promoted βselective glycosylation of unprotected ceramide with a glycosyl methansulfonate. 277 Selective activation of the ceramide 1,3-diol with diphenylborinic anhydride, followed by glycosylation with the corresponding glycosyl mesylates, and subsequent cleavage of the protecting groups afforded GalCer 17 and LacCer 18 in two steps.…”

Section: Chemical Synthesis Of Cerebrosides Sulfatides and Derivativesmentioning

confidence: 99%

“…Various β- C- and β -O- glycoside GalCer analogues have been synthesized, many of which were tested as inhibitors of HIV infection. − For example, sulfatide 12 was synthesized in five steps via glycosylation of azidosphingosine with a trichloroacetimidate donor . Both the β- C- and β -O- glycosides of sulfatide 14 have been synthesized .…”

Section: Chemical Synthesis Of Glycolipidsmentioning

confidence: 99%

Synthetic Strategies for Modified Glycosphingolipids and Their Design as Probes

et al. 2018

View full text Add to dashboard Cite

The plasma membrane of cells contains a diverse array of lipids that provide important structural and biological features. Glycolipids are typically a minor component of the cell membrane and consist primarily of glycosphingolipids (GSLs). GSLs in vertebrates contain a multifarious assortment of glycan headgroups, which can be important to biological functions based on lipid-lipid and lipid-protein interactions. The design of probes to study these complex targets requires advanced synthetic methodologies. In this Review, we will discuss recent advances in chemical and chemoenzymatic synthesis of GSLs in conjunction with the use of these approaches to design new probes. Examples using either chemical or enzymatic semisynthesis methods starting from isolated GSLs will also be reviewed. Focusing primarily on vertebrate glycolipids, we will highlight examples of radionuclide, fluorophore, photoresponsive, and bioorthogonal tagged GSL probes.

show abstract

“…[17] For example, in the case of iGb3 noted above, stannyl alkoxides were needed for efficient addition and a Lewis acid was required to avoid orthoester formation. [8, 18] Other groups have successfully prepared β-linked glycosides from ester-protected glycosyl iodides by using various activating reagents, including NIS/I 2 /TMSOTf (NIS= N -iodosuccinimide, Tf=triflate), [17] I 2 /DDQ (DDQ=2,3-dichloro-5,6-dicyano-1,4-benzoquinone), [19] and NBS/Zn (NBS= N -bromosuccinimide) salts. [20] These methods all have their merits, but the substrates were limited to monosaccharides and, in most cases, long reaction times were required.…”

Section: Introductionmentioning

confidence: 99%

Two‐Step Functionalization of Oligosaccharides Using Glycosyl Iodide and Trimethylene Oxide and Its Applications to Multivalent Glycoconjugates

Hsieh

Davis

Hoch

et al. 2014

Chemistry A European J

View full text Add to dashboard Cite

Oligosaccharide conjugates, such as glycoproteins and glycolipids, are potential chemotherapeutics and also serve as useful tools for understanding the biological roles of carbohydrates. With many modern isolation and synthetic technologies providing access to a wide variety of free sugars, there is increasing need for general methodologies for carbohydrate functionalization. Herein, we report a two-step methodology for the conjugation of per-O-acetylated oligosaccharides to functionalized linkers that can be used for various displays. Oligosaccharides obtained from both synthetic and commercial sources were converted to glycosyl iodides and activated with I2 to form reactive donors that were subsequently trapped with trimethylene oxide to form iodopropyl conjugates in a single step. The terminal iodide served as a chemical handle for further modification. Conversion into the corresponding azide followed by copper-catalyzed azide–alkyne cycloaddition afforded multivalent glycoconjugates of Gb3 for further investigation as anti-cancer therapeutics.

show abstract

Stannyl ceramides as efficient acceptors for synthesising β-galactosyl ceramides

Abstract: beta-Galactosyl ceramides have been obtained in excellent yields and stereoselectivities by reacting disarmed glycosyl donors with stannyl ethers. The broad compatibility of stannyl ethers with various leaving group-promoter pairs is demonstrated.

Cited by 10 publications

References 66 publications

Integrating ReSET with Glycosyl Iodide Glycosylation in Step-Economy Syntheses of Tumor-Associated Carbohydrate Antigens and Immunogenic Glycolipids

Integrating ReSET with Glycosyl Iodide Glycosylation in Step-Economy Syntheses of Tumor-Associated Carbohydrate Antigens and Immunogenic Glycolipids

Synthetic Strategies for Modified Glycosphingolipids and Their Design as Probes

Two‐Step Functionalization of Oligosaccharides Using Glycosyl Iodide and Trimethylene Oxide and Its Applications to Multivalent Glycoconjugates

Contact Info

Product

Resources

About