Synthesis of Monosaccharide Derivatives

Synthesis of Monosaccharide Derivatives.—New approaches to the synthesis of glycosides, including the alkoxylation of N-furanosyl-lactams, the reaction of l-0-acetyl-2,3,5-tri-0-benzoyl-P-D-ribofuranose with cyclic amide acetals derived from vicinal diols (see Vol. 10, p. 16), the Lewis acid-catalysed alcoholysis of sugars with an activated anomeric centre (see Vol. 10, p. 11), and the glycosidation of glycopyranosyl halides catalysed by silver trifluoromethanesulphonate (triflate), have been reviewed. A general review of carbonyl compounds has also dealt with some aspects of glycoside synthesis. 

A novel approach to the synthesis of glycopyranosides has involved the pyrolysis of acylated glycopyranosyl carbonates. Pyrolysis of (27 R = Me or Ph, 

The betaines (28), which are formed in situ from tervalent organophosphorus compounds and diethyl azodicarboxylate, have also been used in the synthesis of glycosides from sugar derivatives having a free anomeric hydroxy-group.  

Hanessian and J. Banoub, Amer. Chem. Soc. Symposium Ser, 1976, 39, Synthetic Methods Carbohydrates Symposium, 36. 

The reaction of 2-0-acetyl-3,4,6-tri-0-methyl-a-D-glucopyranosyl bromide and cyclohexanol in benzene-nitromethane in the presence of mercury(ii) cyanide displayed a first-order dependence on the concentrations of the glycosyl bromide and mercury(ii) cyanide, and the rate of the reaction was independent of the concentration of cyclohexanol. The proportion of P-glycoside in the initial products increased as the concentration of cyclohexanol was increased and the p-glycoside appears to be formed directly from carboxonium ion intermediates and by selective 

Diethyl azodicarboxylate and triphenylphosphine permit the condensation between aldose derivatives with a free reducing centre and phenols. 2,3 5,6-Di-0-isopropylidene-D-mannose gave 67% of the phenyl o-D-mannofuranoside derivative and 16% of the /3-anomer, while 2,3 4,6-di-O-cyclohexylidene-a-D-mannose afforded access to p-nitrophenyl /3-D-mannopyranoside in 58% yield and other, substituted aryl analogues. Unsubstituted sugars can be subjected to the procedure, D-glucose giving mainly the phenyl 3-pyranoside.  

High resolution n.m.r. studies have shown that the phenyl D-glucosides produced by the micro-organism Mucor liemales from phenols are /3-pyranosyl compounds in the expected D-conformation. ° 

Reagents i, HgEr ii, H Hi, TrCl-py iv, TsCl-py v, KOAc-crown ether vi, (PhO)2POCl vii, R-Pt viii, MeO 

Radomiiiska-Pyrek, M. Pilarska, and P, Zimniak, Biochem. Biophys. Res. Commun., 

Garegg and T. Norberg, Acta Chem. Scand., SerB., 1979, 33, 116. 

Nambara, J. Goto, H. Furuyama, and H. Kato, Chem. and Pharm. Bull. Japan), 1978, 26, 591. 

Lipids, 1977, 19, 347 Chem. Abs., 1978, 88, 23 323p). 

In the uronic acid series, glucuronides of phenolphthalein, iV-hydroxy-4-aminobiphenyl, and the methaqualone metabolite (13) have been synthesized by standard Koenigs-Knorr procedures. 

---

Considerable effort has heen directed towards the synthesis of monosaccharide derivatives, and, in particular, C-glycosyl compounds, from Diels-Alder adducts offuran. Just and his group investigated the reaction of furan with a number of dienophiles, and described many interesting transformations of the adducts obtained from... 

A fundamentally different approach to the total synthesis of monosaccharide derivatives from 417, based on the telomerization principle, was elaborated by Kunieda and coworkers.278,277 These authors... 

He also investigated the synthesis of monosaccharide derivatives containing polymerizable constituent groups and their polymerization (1961-1970), and grafted carbohydrate units onto polysaccharides (1962-1970). 

Finally, because the 1,1-difluoro-l-deoxy derivative of cellobiose was required for kinetic studies of cellobiohydrolases, we examined the reaction of the corresponding diazirine with XeF2. A method for the synthesis of monosaccharide-derived anomeric difluorides has been described by Praly [53, 54], but seems unsuitable for the synthesis of disaccharide-derived analogs. 

S. S. Thomas, J. Plenkiewicz, E. R. Ison, M. Bols, W. Zou, W. A. Szarek, and R. Kisilevsky, Influence of monosaccharide derivatives on liver cell glycosaminoglycan synthesis 3-deoxy-D-xylo-hexose (3-deoxy-o-gaIactose) and methyl (methyl 4-chloro-4-deoxy- 3-D-galacto-pyranosid)uronate, Biochim. Biophys. Acta 1272 37 (1995). 

A. Banaszek and A. Zamojski, Derivatives of 2-alkoxy-5,6-dihydro-a-pyran as substrates in the synthesis of monosaccharides. 5. Direction of oxirane ring opening in methyl... 

Workers targeting thietanyl nucleosides via the Pummerer reaction have reported a [3+1] synthesis of thietanose derivatives (i.e., thietane ring-based monosaccharides). Nishizono et al. performed the synthesis of... 

A true chemical synthesis of specific oligosaccharides had to await the discovery of monosaccharide derivatives that were suitable as starting... 

Semi-synthesis of Pyranose derivatives Small acyclic components, C5 and C6 alicyclic compounds have been employed as intermediates in addition to the readily available monosaccharides such as glucose or mannose, in this context these intermediates are template structures. 

The methods of synthesis of methylated derivatives of amino sugars are, in general, the same as those used for the preparation of methylated derivatives of other monosaccharides and are described in previous articles of this Series. 

The first research project that Alex undertook in the Institute was directed to the chemistry of the macrolide anitibiotic, erythromycin. Chemical modifications led to a new derivative, 8-hydroxyerythromycin, a patent on which was purchased by a major pharmaceutical company. At the same time, Alex initiated studies on the total synthesis of monosaccharides via the Diels-Alder adduct of... 

Tetroses and Pentoses - 4-0- -Butyldimethylsilyl-2,3-0-isopropylidene-L-threose (1) has been prepared in seven efficient steps from o-xylose. 3,4-0-Isopropylidene-D-eythrulose (4) has been synthesized from the known tetritol derivative 2 by primary protection as the silyl ether 3, followed by Dess-Martin oxidation and desilylation. Compound 2 was derived from D-isoascorbic acid (see Vol. 22, p. 178, refs. 9,10). In a similar reaction sequence, the enantiomer 5 has been obtained from L-ascorbic acid. The dehomologation of several di-0-isopropylidenehexofuranoses e.g., 6- 7) has been carried out in two steps without intermediate purification, by successive treatment with periodic acid in ethyl acetate, followed by sodium borohydride in ethanol. Selective reduction of 3-deoxy-D-g/jcero-pentos-2-ulose (8) to 3-deoxy-D-g/> cero-pent-2-ose (9) has been achieved enzymically with aldose reductase and NADPH." 4-Isopropyl-2-oxazolin-5-one (10) is a masked formaldehyde equivalent that is easily converted to an anion and demasked by mild acid hydrolysis. One of the three examples of its use in the synthesis of monosaccharides is shown in Scheme 1. ... 

From Chiral Non-carbohydrates - A section on amino-sugars has been included in a review of the synthesis of monosaccharides from non-carbohydrate sources. L-Ristosamine 42 was synthesized by addition of the Cs-synthon 40 (which contains a masked aldehyde function that can be readily demasked by mild acid hydrolysis) to the L-lactaldehyde derivative 41 (Scheme 11). The TBSOP adduct 43 (Vol.27, p.ll4), derived from 2,3-< -isopropylidene-D-glycer-aldehyde, has been converted into 3-amino-3-deoxy-D-altrose 46 by a route involving cis-hydroxylation of its unsaturated lactam moiety and periodate cleavage between C-6 and C-7 of the derived heptitol derivative 45 as key steps (Scheme 12). 3-Amino-3-deoxy-L-allose was obtained by converting 43 to its C-3... 

As before, this Chapter deals with specific trl- and higher saccharides most references related to their syntheses by specific chemical methods. It does not cover higher, non-specific compounds made by the oligomerisation of monosaccharide derivatives nor does it deal with the cyclodextrins. The synthesis of, e.g.. pentasaccharides is dealt with under that heading and the required preparations of constituent parts are assumed and are not covered in their sections. 

Scheme 6.26 Synthesis of furfural derivatives from a variety of monosaccharides.

---