4 edition of C-Glycoside synthesis found in the catalog.
Includes bibliographical references and index.
|Statement||Maarten H.D. Postema.|
|Series||New directions in organic and biological chemistry|
|LC Classifications||QP702.G59 P67 1995|
|The Physical Object|
|Pagination||379 p. :|
|Number of Pages||379|
|LC Control Number||94041409|
There is no example of C-glycoside synthesis promoted by GHs reported in the literature so far, although as depicted by the mechanism, this kind of biocatalysed reaction can be envisioned. Conclusion To conclude, the enzymatic mechanisms that rule the activities of GTs and GHs begin to be well understood by the glycoscientists. Thieme E-Books & E-Journals. C-Glycoside formation of mono-protected resorcinols is ent of mono-O-acyl resorcinols with glycosyl fluoride 1 (2,3,5-tri-O-methyl-α-D-ribofuranosyl fluoride) at °C in the presence of diethyl ether-boron trifluoride or hafnocene dichloride/silver perchlorate led to rapid formation of the O-aryl glycoside.
involve the synthesis of a ring after the formation of a C-glycoside. Nonnucleosidic C-glycosides also have been synthesized.[36,37] Thiol-carrying aryl C-glycosides have also been prepared by non-Heck methods. The synthesis of unsaturated glycals, precursors for the reactions dis-cussed here, recently was reviewed. Title: Recent Advances in Aryl C-Glycoside Synthesis VOLUME: 5 ISSUE: 14 Author(s):David Y. W. Lee and Minsheng He Affiliation:Bioorganic and Natural ProductsLaboratory, McLean Hospital, Harvard Medical School, Mill Street,Belmont, MA Keywords:de-O-methylation, Glycosyl halides, Lactones, Cyclization, intramolecular tether approach, umpolung.
C-Glycosyl-(S)- and (R)-alanines 12a and 12b were synthesized from the known β-C-glycoside 1. The nitrogen function was introduced by aza-Claisen rearrangement of the allylic thiocyanate 7, derived from the corresponding alcohol 6. The absolute configuration of the newly created chiral carbon center (C-3) was assigned by X-ray diffraction analysis of the intermediate 3(S)-isothiocyanato-D Cited by: 2. C-Glycoside Synthesis 1st Edition. Maarten Postema Febru This book examines methods particularly well suited for either a- or b-C-glycoside formation. It helps field workers quickly select the best method for synthesizing a particular type of C-glycoside. The use of C-glycosides as synthons in natural product synthesis is also.
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Book Description. This book examines methods particularly well suited for either a- or b-C-glycoside formation. It helps field workers quickly select the best method for synthesizing a particular type of C-glycoside.
The use of C-glycosides as synthons in natural product synthesis is also addressed. C-Glycoside Synthesis (New Directions in Organic & Biological Chemistry) 1st Edition by Maarten Postema (Author)Cited by: Buy Synthesis of C-Glycosides via Ramberg-Backlund Reaction: Synthesis of C-Glycosides KRN on FREE SHIPPING on qualified orders.
Electrophilic Sugars in C-Glycoside Synthesis I -- Ch. Electrophilic Sugars in C-Glycoside Synthesis II -- Ch. C-1 Nucleophiles in C-Glycoside Preparation -- Ch. Wittig Approaches to C-Glycoside Formation -- Ch.
Palladium Mediated Approaches to C-Glycosides -- Ch. Concerted Reactions Applied to C-Glycoside Preparation -- Ch. The majority of the methods take advantage of the construction of the glycosidic C—C bond. These C -glycosylation methods are categorized herein in terms of the glycosyl donor precursors, which are commonly used in O -glycoside synthesis and are easily accessible to nonspecialists.
They include glycosyl halides, glycals, sugar acetates, sugar lactols, sugar lactones, 1,2-anhydro sugars, Cited by: Synthesis of C- and S-Glycosides Alternatively the anomeric center of the sugar can be activated by conversion of the hydroxyl group to a better leaving group X (18 in Scheme 3), usually an.
This book provides a broad coverage of the various synthetic methods available for the preparation of C -glycosides, and illustrates the interesting breadth of connections between carbohydrate.
from book Synthesis and A glycoside is defined as C-glycoside when what is supposed to be the anomeric carbon of a sugar is interconnected to the aglycon, generating a new C–C bond. Synthesis of C -glycoside by Negishi cross coupling approach.
Hayashi and co-workers developed an asymmetric synthesis of optically active cis - and trans arylmethylpyrans from commercially available tetra- O -acetyl- d -glucopyranosyl by: A series of novel monoacylated vitamin C derivatives were chemically synthesized with a stable ascorbate derivative, 2-O-α-d-glucopyranosyl-l-ascorbic acid (AA-2G), and acid anhydrides in pyridine.
Their solubility in organic phase, thermal stability, radical scavenging activity, and in vitro skin permeability was evaluated. These monoacylated derivatives were identified as 6-O-acylO-α-d Cited by: This book provides a broad coverage of the various synthetic methods available for the preparation of C -glycosides, and illustrates the interesting breadth of connections between carbohydrate chemistry and modern general synthetic.
and co-workers  on the synthesis of C-manno-pyranoside and C-galactosamine derivatives con-ﬁrmed that the approach using 2-pyridyl sulfone is a useful method for the C-glycoside synthesis of aldoses. Encouraged by the reports of Sinay¨ and Wong  on the samarium-mediated coupling of - alkoxy sulfones with ketones, and glycosyl phos.
Glycosylation of Silylated Compounds as Glycosyl Acceptors. Two‐Stage Activation Procedure. Protecting‐Group‐Based Strategy. Application to Natural Product Synthesis. Special Topics C‐Glycoside Synthesis via O‐Glycosylation Glycosyl Fluorides for the Synthesis of a Combinatorial LibraryCited by: 9.
Treatment of peracetylated glycals with olefins in the presence of Lewis acids gave 2,3-unsaturated -glycosides in good to excellent yields. The reaction was completely regioselective and showed a high degree of stereoselectivity leading mostly to the α-isomer.
Generally the addition gave the. This chapter reviews the synthesis of C -furanosides of the galacto - configuration series. Approaches include nucleophilic and radical additions, reductions at the anomeric carbon, hydrogenation of exo -glycals, stereospecific and stereoselective cyclization reactions, stereochemical inversions at C-2 or C-3, and cycloaddition reactions.
A glycoside is defined as C-glycoside when what it is suppose to be the anomeric carbon of a sugar is interconnected to the aglycon, generating a new C-C bond.
According to Levy and Tang the term C -glycoside describes those structures in which a common structural motifs the presence of carbon functionality at what would otherwise be the. Abstract. C-glycosides have attracted much attention, considering that many of them have demonstrated their effectiveness as therapeutic increasing significance of C-glycosides is that the conformational differences compared to O- or N-glycosides are minimal, and that they are resistant to enzymatic or acidic hydrolysis since the anomeric center has been transformed from acetal to.
This book contains the best known approaches for preparing the main types of glycosides in a short and comprehensive study.
It also includes synthetic pathways of challenging glycosides known as antiviral or antineoplasic drugs, or synthetic substrates used for enzymatic detection including those used as substrates for detection of gene markers in plant s: 1.
A short, stereoselective method for generation of the fused C-glycoside unit of the anticancer agent nogalamycin is described; in particular, synthesis of the D,E,F ring system. The method utilises a total synthesis of the glycosidic unit from an aryl furyl alcohol.
The indium-mediated alkynylation of perbenzylated or peracetylated formylglucose is a pathway for the synthesis of various C-glycosides. Hydroxylated, ketonic, mono- or difluorinated, and methylated C-glycosides were thus by: 5.
Enzymatic C-glycoside bond formation: The C-glycoside synthases encoded in the formycin and pyrazofurin biosynthetic gene clusters are identified and compared by genomic analysis of the producing strains. Both enzymes catalyze decarboxylative C-glycoside bond formation between phosphoribosyl pyrophosphate and a pyrazole nucleobase in reactions likely to involve electrophilic Author: Daan Ren, Shao‐An Wang, Yeonjin Ko, Yujie Geng, Yasushi Ogasawara, Hung‐wen Liu.This book provides a broad coverage of the various synthetic methods available for the preparation of C-glycosides, and illustrates the interesting breadth of connections between carbohydrate chemistry and modern general synthetic organic chemistry by including topics such as transition-metal catalysis, radical chemistry, cycloaddition and rearrangement processes.Abstract.
The stereoselective syntheses of three cyclitols, 5a-carba-α-d-rhamnopyranose, 5a-carba-β-d-digitoxopyranose, and 5a-carba-α-l-rhamnopyranose, have been routes rely upon a Simmons-Smith cyclopropanation and diastereospecific ring opening of cyclopropanol under Pd/C hydrogenation conditions to prepare the α-methyl by: 4.