Monosaccharides compounds

That bromine atoms can be introduced directly at C-5 of some pyranoid compounds, at C-4 of some furanoid derivatives, and at chemically related centers of certain other monosaccharide compounds was discovered following the finding by Dr. Richard Fumeaux, during his Ph.D. studies in Wellington, that phenyl tetra-O-acetyl-1 -thio-/i-D-glucopyranoside (1) is con-... 

Modified monosaccharides. Compounds such as halodeoxy-, aminodeoxy-, thio- and anhydrosugars, glycuronic acids, etc. are covered extensively. 

A wide range of glucal and alkyl 2,3-dideoxy-D-co t/rr< -hex-2-enopyranoside derivatives have been reported in a study of the preparation of monosaccharide compounds containing two double bonds. 6-Sulphonyl esters of D-glucal could be converted into analogues with 6-deoxyalk-5-ene functionality by way of 6-deoxy-6-iodo intermediates, but corresponding methods did not lead to 2,3 5,6-di-unsaturated products. ... 

The most general methods for the syntheses of 1,2-difunctional molecules are based on the oxidation of carbon-carbon multiple bonds (p. 117) and the opening of oxiranes by hetero atoms (p. 123fl.). There exist, however, also a few useful reactions in which an a - and a d -synthon or two r -synthons are combined. The classical polar reaction is the addition of cyanide anion to carbonyl groups, which leads to a-hydroxynitriles (cyanohydrins). It is used, for example, in Strecker s synthesis of amino acids and in the homologization of monosaccharides. The ff-hydroxy group of a nitrile can be easily substituted by various nucleophiles, the nitrile can be solvolyzed or reduced. Therefore a large variety of terminal difunctional molecules with one additional carbon atom can be made. Equally versatile are a-methylsulfinyl ketones (H.G. Hauthal, 1971 T. Durst, 1979 O. DeLucchi, 1991), which are available from acid chlorides or esters and the dimsyl anion. Carbanions of these compounds can also be used for the synthesis of 1,4-dicarbonyl compounds (p. 65f.). 

Enantiomerically pure tetroses, pentoses, and hexoses have been synthesized by the following reaction sequence (A.W.M. Lee, 1982 S.Y. Ko, 1983), which is useful as a repetitive two-carbon hotnologi-.ation in total syntheses of higher monosaccharides and other polyhydroxy compounds (1) Wittig reaction of a protected hydroxy aldehyde with (triphenylphosphor-... 

Antibiotic A201A. Antibiotic A201A (23), produced by S. capreolus is an /V -dimethyladenine nucleoside stmcturaHy similar to puromycin (19). Compound (23) which contains an aromatic acid and monosaccharide residues (1,4), inhibits the incorporation of amino acids into proteins but has no effect on RNA or DNA synthesis. Compound (23) does not accept polypeptides as does (19), and does appear to block formation of the initiation complex of the SOS subunit. It may block formation of a puromycin-reactive ribosome. 

Recently, various monosaccharides have been employed as a source of 1,4-dicarbonyl compounds for pyridazine syntheses 70CB1846, 74CPB1732, 75JHC957). Moreover, diacylcyc-lopropanes have been also reported to give pyridazines the bicyclic products are transformed by P4S10 into the corresponding 3-thioxopyridazines 80JHC541). 

COLLECTION AND IDENTIFICATION OF BIOACTIVE ORGANIC COMPOUNDS OCCURRING IN RIVERS AND LAKES. ADSORPTION SELECTIVITY OF MONOSACCHARIDES ONTO HYDROUS METAL OXIDES... 

As a possible method of concentrating trace amounts of bioactive organic compounds occurring in the hydrosphere, adsorption properties of various compounds have been explored by employing hydrous metal oxides as the adsorbents. To date, a family of organophosphoms compounds and carbonic acids were adsorbed onto hydrous iron oxide, along with the adsoi ption of monosaccharides onto hydrous zirconium oxide. 

Sucrose, the compound we call sugar, is the most common disaccharide. One of the monomer units in sucrose is a-glucose. The other is fructose, a monosaccharide found in honey and natural fruit juices. 

Reaction of hydrazine 165 with a number of monosaccharides give hydrazones 166 (92BCJ546). Their acetylations gave peracetyl derivatives 167. The same reactions were extended to the /V-methyl and the 7-methyl derivatives of 165 (93 JPROO). That compounds 166 exist as open-chain structures was based on a 2D NMR study (93MI1) (Scheme 35). 

The generic term monosaccharide (as opposed to oligosaccharide or polysaccharide) denotes a single unit, without glycosidic connection to other such units. It includes aldoses, dialdoses, aldoketoses, ketoses and diketoses, as well as deoxy sugars and amino sugars, and their derivatives, provided that the parent compound has a (potential) carbonyl gTOup. 

Monosaccharides in which an alcoholic hydroxy group has been replaced by an amino group are called amino sugars (see 2-Carb-14). When the hemiacetal hydroxy group is replaced, the compounds are called glycosylamines. 

The compounds usually known as monosaccharide anhydrides or glycose anhydrides (earlier glycosans ), formation of which involves the anomeric hydroxy group, are named by the same procedure. In these cases the order of preference of ring size designators is pyranose > furanose > septanose. However, three- or four-membered rings should normally be cited as anhydro if there is a choice. 

A disaccharide is a compound in which two monosaccharide units are joined by a... 

De Bruijn et al.26 30 used chromatographic and spectroscopic techniques to analyze the effect of reaction variables (such as pH and monosaccharide concentration) on the product profile and developed a reaction model (see Fig. 9) that emphasized the role of a-dicarbonyl compounds. Some of the features of the model shown in Fig. 9 are ... 

Pyran derivatives, useful intermediates in the total synthesis of many monosaccharides and other natural products, have been synthesized by hetero-Dish-Alder reaction by using carbonyl compounds as dienophiles [9, 23]. 

Polyhydroxypyrrolidines 7 to 12 represent a group of compounds having only a marginal resemblance to monosaccharides, but which are, neverthe-... 

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