Carbohydrate Chemistry

Transcription

1 Carbohydrate Chemistry edited by Geert-Jan Boons University of Birmingham Birmingham UK m BLACKIE ACADEMIC & PROFESSIONAL An Imprint of Chapman & Hall London Weinheim New York * Tokyo Melbourne Madras

2 Contents 1 Mono- and Oligosaccharides: structure, configuration and conformation 1 G.-J. BOONS 1.1 Introduction Configuration of Monosaccharides Conformational propertiesof monosaccharides Ring shapes of py ranoses and furanoses The anomeric effect The equilibrium composition of monosaccharides in Solution Conformational propertiesof Oligosaccharides 16 References 18 2 Protecting group strategies for carbohydrates 21 T. ZIEGLER 2.1 Introduction Protection of the anomeric centre Acyl protecting groups Regioselective acylation and deacylation of carbohydrates Combination of different 0-acyl groups as orthogonal sets JV-acyl groups for glycosamines Ether protecting groups Benzyl and substituted benzyl groups Allyl ether groups Silyl ether groups Acetal protecting groups 38 References 40 3 Functionalized saccharides 46 G.-J. BOONS and B. HESKAMP Introduction Amino sugars Introduction The preparation of amino sugars by nucleophilic displacements Nucleophilic ring opening of epoxides Addition to glycals Reductionofoximes Intramolecular substitutions Sulphated saccharides Introduction Monosulphation Regioselective sulphation Polysulphation Selective Af-sulphation Phosphorylated saccharides Introduction Non-anomeric sugar phosphates

3 VI Anomeric phosphates Deoxy sugars Introduction Reduction of halides and sulphonates Radical deoxygenation Addition to glycals Reductiveopeningofepoxides 83 References 83 Chemical synthesis of O-glycosides 98 G.H. VEENEMAN 4.1 Introduction General principles Protecting groups Solvent aspects Glycosidation procedures 'Labile' glycosyl donors 'Stable' glycosyl donors Synthesis of /?-mannopyranosides Synthesis of 2-deoxy-2-acetamido-glycopyranosides js-linked O-glycosides from 2-acetamido-gluco- and galactopyranose a-linked O-glycosides from 2-acetamido-gluco- and galactopyranose Linked2-acetamido-mannopyranosides Glycosidation of 3-deoxy-2-keto-ulo(pyranosyl)onates Formation of 2-deoxy-glycosidic linkages 164 References 167 Strategies and tactics in Oligosaccharide synthesis 175 G.-J. BOONS 5.1 Introduction Linear glycosylation strategies Convergent block synthesis Selective and two-stage activation and orthogonal glycosylation strategies Chemoselective glycosylation reactions Latent-active glycosylation strategies One-pot multistep glycosylations Solid-phase Oligosaccharide synthesis Combinatorial Oligosaccharide synthesis Enzymatic and semi-synthetic glycosylation strategies Introduction Glycosyl transferases Glycosyl hydrolases Chemo-enzymatic methods 211 References 214 The chemistry of O- and N-linked glycopeptides 223 G.-J. BOONS and R.L. POLT 6.1 Introduction Chemical synthesis of serine 0-glycoside derivatives 224

4 Vll 6.3 The synthesis ofiv-glycopeptides Solution- and solid-phase glycopeptide synthesis Enzyme-mediated glycopeptide synthesis 236 References 238 The chemistry of neoglycoconjugates 243 R. ROY 7.1 Introduction Classesof neoglycoconjugates Glycan fragments derived from natural conjugates as neoglycoconjugate precursors Neoglycoproteins and neoglycopeptides Neoglycoproteins Neoglycopeptides Neoglycopeptidolipids Neoglycolipids and liposomes Neoglycolipids Liposomes and polymerized liposomes Glycopolymers Polymerization methods Polysialosides Enzymatic glycosylation of glycopolymers Biological applications Glycodendrimers Other glycoforms Conclusion 310 References 311 Chemistry of cyclic Oligosaccharides 322 S.A. NEPOGODIEV and J.F. STODDART 8.1 Introduction Classification and nomenclature of cyclic Oligosaccharides Cyclodextrins Structure and properties of cyclodextrins Chemical modifications of cyclodextrins Naturally occurring and enzymatically produced cyclic Oligosaccharides Synthetic cyclic Oligosaccharides Some final observations 371 References 371 Modified carbohydrates and carbohydrate analogues 384 F. NICOTRA 9.1 Introduction Biological interest The modifications Classification of carbohydrates with anomeric modifications Carbasugars Carbasugars from Diels-Alderadducts Carbasugars from cyclohexyl or cyclopentyl derivatives Carbasugars from natural sugars C-glycosides 399

5 Vlll C-glycosylation by reaction of glycosyl halides or epoxides with organometallics or carbanions C-glycosylation by 'glycoenitol' cyclization Lewis-acid catalysed C-glycosylations C-glycosides from glyconolactones C-glycosides by cyclization ofdiols and derivatives C-glycosides from glycosyl radicals C-glycosides from glycosyl anions and glycosyl metallic reagents C-glycosides by allylic Substitution Azasugars Azasugars via anomeric amination Azasugars via chain amination Azasugars from aminosugars Azasugars from non-carbohydrate starting materials JV-iminosugars Thiosugars Phosphasugars Cyclic phosphonate analogues of carbohydrates Analogues with phosphorus in place of the glycosidic oxygen Oligosaccharide mimics Conclusions 421 References Naturally occurring saccharides: targets for new therapeutics 430 E.F. HOUNSELL 10.1 Introduction Naturally occurring saccharides the terminology Blood group and related antigens Synthesis and conformational studies of backbones and non-reducing termini of glycoconjugate Oligosaccharide chains Synthesis and conformational studies of high mannose, hybrid and complex TV-linked glycoprotein chains The proteoglycans: structure, function and synthesis of their glycosaminoglycan (GAG) chains The glycoconjugates of micro-organisms and their host receptors: targets for new therapeutics and vaccines 440 Acknowledgement 442 References Physical methods in carbohydrate research 448 G. WIDMALM 11.1 Introduction Nuclear magnetic resonance spectroscopy Introduction The spin System Homonuclear assignments Heteronuclear assignments Sequence assignments NMR experiments for conformational analysis Mass spectrometry Introduction Electron impact Fast atom bombardment 471

6 Electrospray ionization Atmospheric pressure chemical ionization Matrix-assisted laser desorption ionization Circular dichroism spectroscopy X-ray ( urystallography Molecular modelling Acknowledgements References Introduction Definitions Force fields Energy minimization Monte Carlo simulations Molecular dynamics Langevin dynamics Quantum mechanics IX Index 503