Carbon−Carbon Bond Formations Involving Organochromium(III) Reagents

Macrolactonizations in the Total Synthesis of Natural Products

A DISCUSSION OF CARBOHYDRATE CHEMISTRY An Historical Overview R.J. Ferrier Introduction to Carbohydrates J. Kuszmann Protective Group Strategies S. Oscarson Glycosylation Methods P. Fugedi Oligosaccharide Synthesis P. Fugedi FROM SUGARS TO SUGAR-LIKE STRUCTURES TO NON-SUGARS Functionalization of Sugars D.E. Levy Strategies Towards C-Glycosides D.E. Levy From Sugars to Carba-Sugars M. Sollogoub and P. Sinay Sugars with Endocyclic Heteroatoms Other than Oxygen P. Greimel, J. Spreitz, F.K. Sprenger, A.E. Stutz, and T.M. Wrodnigg SUGARS AS TOOLS, CHIRAL POOL STARTING MATERIALS AND FORMIDABLE SYNTHETIC TARGETS Sugars as Chiral Auxiliaries N. Pleuss, G. Zech, B. Furman, and H. Kunz Sugars as Chiral Starting Materials in Enantiospecific Synthesis Y. Chapleur and F. Chretien Synthesis of Carbohydrate Containing Complex Natural Compounds K. Toshima Total Asymmetric Synthesis of Monosaccharides and Analogs P. Vogel ADDITIONAL TOPICS Combinatorial Carbohydrate Chemistry P. Arya and B. VNBS Sarma Glycopeptides M. Mogemark, J. Kihlberg Carbohydrate Mimetics in Drug Discovery O. Schwardt, H.C. Kolb, and B. Ernst

The Organic Chemistry of Sugars

Deoxysugars and the oligosaccharides derived from them belong to one of the most important, but often most neglected, group of biological compounds. As a result of important recent progress in their chemical synthesis as well as insights into their various biochemical aspects, one can expect a major boom in the amount of research devoted to this promising field. In this chapter, the most significant aspects of the biochemistry and chemistry of deoxysugars and deoxysugar-containing oligosaccharides are discussed: (1) biosynthetic, biochemical, and molecular biological studies, including deoxygenation mechanisms, glycosyl transfer, and genes involved in biosynthesis; (2) recent experiments aimed at determining how monoor oligosaccharide moieties of bioactive natural products contribute to biological activity, i. e., the mode of action of these compounds; and (3) synthetic aspects such as chemical glycosidation and enzymatic methods for the construction of deoxysugar oligosaccharides. The information presented here is based on literature published until mid-1996.

Chemical and biochemical aspects of deoxysugars and deoxysugar oligosaccharides

Mutations in subunit C of the vacuolar ATPase confer resistance to bafilomycin and identify a conserved antibiotic binding site

The highly stereoselective total synthesis of the macrolide antibiotic, bafilomycin A1 (1), the first specific potent inhibitor of vacuolar H+-ATPase, has been achieved by a convergent route involving the synthesis and coupling of its 16-membered tetraenic lactone and β-hydroxyl hemiacetal side-chain subunits. The C1−C17 16-membered lactone aldehyde 2 was synthesized through the coupling of the C5−C11 vinyl iodide 4 and the C12−C17 vinylstannane 5, followed by construction of the C1−C4 diene and macrolactonization. The aldol coupling of 2 and the C18−C25 ethyl ketone 3 followed by desilylation provided 1, which was identical with natural bafilomycin A1. The key synthetic segments 3−5 were effectively synthesized from the readily available chiral materials, d-glucose, ethyl (S)-lactate, and methyl (S)-3-hydroxy-2-methylpropionate, respectively.

Total synthesis of bafilomycin A1

De novo highly stereocontrolled synthesis of 2,6-dideoxy sugars by use of 2,6-anhydro-2-thio sugars

Application of efficient glycosylation of 2,6-anhydro-2-thio sugar to the total synthesis of erythromycin A

De novo highly stereocontrolled synthesis of 2,6-dideoxy-C-3-branched carbohydrates by use of 2,6-anhydro-2-thio sugar : L-cladinose and its C-3 epimer

Takehito Yoshida

Papers

Total synthesis of bafilomycin A1

De novo highly stereocontrolled synthesis of 2,6-dideoxy sugars by use of 2,6-anhydro-2-thio sugars

Application of efficient glycosylation of 2,6-anhydro-2-thio sugar to the total synthesis of erythromycin A

De novo highly stereocontrolled synthesis of 2,6-dideoxy-C-3-branched carbohydrates by use of 2,6-anhydro-2-thio sugar : L-cladinose and its C-3 epimer

Total Synthesis of Bafilomycin A1.