Glycal

About: Glycal is a research topic. Over the lifetime, 897 publications have been published within this topic receiving 17422 citations.

Enzymatic process for producing a galactosyl beta 1,3glycal disaccaride using beta -galactosidase

Abstract: An enzymatic process is disclosed for the preparation of galactosyl beta 1,3glycal disaccharides such as Gal beta 1,3Glucal, an intermediate useful in Lea preparation and an inhibitor of beta -galactosidase. The process utilizes beta -galactosidase, an enzyme usually used for bond breaking, to form a bond between a galactoside and a glucal such as glycal, a 6-O-C1-C6 acylglucal or 6-O-C1-C6 acetylgalactal.

Novel Glycosylation of Aromatic Amines Through 1, 2-Anhydrosugars

Abstract: A new and novel bismuth nitrate and indium bromide-catalyzed glycosylation of aromatic amines with glycal epoxides is described in moderate yield. Despite the poor nucleophilicity of the aromatic amines, the success of this reaction is noteworthy.

Chapter 12 The invention of the alkynol cycloisomerization reaction: Application to the synthesis of digitoxin

Abstract: Publisher Summary The first synthesis of carbohydrate-derived cyclic enol ethers (glycals) was developed by Emil Fischer early in the 20th century, featuring reductive elimination of glycosyl halides from carbohydrate starting materials. A newer approach to glycals features ring-closing metathesis of vinyl ethers with terminal alkenes. The development of methods for glycal synthesis has been accompanied by studies on the regio- and stereoselective functionalization of glycals, which can be applied to the introduction of functional groups at the 2-position. Thus, an endo-regioselective “alkynol cycloisomerization” process would provide another pathway to the synthesis of various cyclic enol ethers, including possibly glycals, if a reaction that is compatible with a variety of functional groups can be developed. With the discovery of six-membered ring formation via tungsten carbonyl reagents, the possibilities of synthesizing not only hexose sugars but also glycosides were considered. To test for the compatibility of alkynes with glycoside-forming methodologies, a microscale experiment with iodoglycosylation of chiral non-racemic alkynyl alcohol with commercially available tri-O-acetyl-D-glucal (25) has been conducted. The product iodoglycoside was observed as a single diastereomer by 1H-nuclear magnetic resonance (NMR) analysis of the reaction mixture.

Method for preparing enzymatic substrate analogs as inhibitors of bacterial heptosyl-transferases

Abstract: The invention relates to a A method for making osyl and hexoses derivatives of formula 1 , especially 2-fluoro-2-deoxy derivatives. wherein R is a nucleoside such as adenosine, cytidine, guanosine, uridine and deoxy analogs such as 2-deoxy, X represents OH, halogen, particularly F, NH 2 Y represents H, CH 2 OH, CH 2 NH 2 , CH 2 OPO 3 , CH 2 OSO 3 Z represents O or S, and W represents O, NH, or CH 2 , said method comprising the steps of: a) stereoselective fluorophosphorylation of tetrapivaleate 8 to give β-gluco-type fluorophosphate, b) hydrogenation and deprotection to give a monophosphate, c) coupling said glycal with (R)P-morpholidate to give crude sugar nucleotide 1 , or alternatively, d)deacetylation then silylation of heptaglycal 7 to give tetrasilylated glycal, e) fluorophosphorylation of said glycal to give β-gluco type fluorophosphate, f) deprotection of the fluorophosphate and coupling radical R to give 1 . Use of said derivatives as inhibitors of highly virulent proteins of pathogenic bacteria.