Synthesis of Disaccharides and their Derivatives

The very interesting glycophane 47 has been synthesized from a trehalose 6,6 -ditriflate and found 

Reagents i, MeiSiCl2. EtsN ii, 5-phenyl-3,4,6-tri-0-acetyl-l-thio-a-I glucopyianoside. Py iii,NIS,MeN02 

D-glucopyranoside electrolysed in an undivided cell in dry acetonitrile with primary or secondary carbohydrate alcohols give good yields of mainly /3-linked disaccharide products. 

Dextransucrase from a Streptococcus, besides forming polymers, can be used as a glycosylating catalyst to transfer glucose units to acceptor substrates. Methyl a-D-glucopyranoside is thereby converted into the 1,6-a-linked dimer and methyl 6-bromo-6-deoxy-cK-D-glucopyranoside is glycosylated by way of a a-1,3-linkage. 

Reagents i, R 02CN=NC02R t A ii, MeOH, BF3. Et20 iii, BnOH, NaH iv, Raney Ni, H2 v, AC2O 

2 Synthesis of Dlsaccharldes and their Derivatives.- Provisional recommendations have been made for abbreviations to be used for the representation of oligosaccharide chains.In the following, compounds are classified according to their non-reducing components but on several occasions it has proved beyond the scope of this treatment to refer to every disaccharide synthesized. 

Methods of synthesis of a-linked D-glucose disaccharides continue to attract attention and tetra-O -benzyl-a-D-glucopyranosyl chloride used in the presence of silver imidazolate and mercury(II) chloride gave, with l,2 3, -di-0-isopropylidene-a-D-galactose and 1,2 5,6-di-O-isopropylldene-a-D-glucofuranose, products containing more than 50% of the a-llnked disaccharides. Considerably 

Various D-glucose-contalning disaccharide derivatives have been prepared mainly for biochemical work. These include the 2-( -amlnophenyDethyl glycosides of the a- and 3- (1 2) and (1 - 3) 

Several other dlsacharldes produced by use of a 2-amlno-2-deoxy-D-glucosylating agent have been reported. Improvements In the 

In the area of D-mannopyranosyl disaccharides, 2,3 4,6-di-O-cyclohexylidene-a-D-mannopyranosyl chloride in the presence of silver imidazolate and mercury(II) chloride leads to moderate yields  

Synthesis of Disaccharides and their Derivatives. — In this Section compounds are categorized according to the nature of the non-reducing sugars other disaccharide syntheses are referred to in the next Section. 

Reduction of 3-ketosucrose with sodium borohydride gives mainly a-D-allopyranosyl-jS-D-fructofuranoside, and deuterium can be incorporated by this approach. Various derivatives of the disaccharide were prepared, including the 6,1, 6-tritrityl ether, the 6,6-ditrityl ether, the penta-acetate, and the hexa-acetate derivable from these, and the 6,6-dichloro-6,6-dideoxy-compound,  

In the area of non-reducing disaccharides it has been found that treatment of 2,3,4,6-tetra-0-benzyl-D-gluco5e, -D-mannose, and -D-galactose with trifluoro-acetic anhydride in DMF gives the a,a- and a,/3-dimers in the ratio 2 1 (the method can also be applied to give heterodisaccharides).0 ,o -Trehalose has been converted by way of the 6,6 -ditrityl ether and its hexa-acetate into the 

2-Thio-orthoesters in the D-gluco-, D-galacto-, D-manno-, and L-rhamno- 

The disaccharide dipeptide (7) was synthesized by initial condensation using 

Synthesis of Disaccharides and their Derivatives. — A survey of methods of synthesis of oligosaccharides has appeared, as has a brief review of the general chemistry of these compounds. 

Nozaki, T. Ogawa, and M. Matsui, Tennen Yuki Kagobutsu Toronkai Koen Yoshishu, 21st, 1978, 213 (Cherru Abs., 1979, 90, 168908 ). 

2-0-a-D-Mannopyranosyl- 3-D-mannopyranose and 6-O-a-D-mannopyranosyl-o -D-mannopyranose have been prepared by Koenigs-Knorr procedures as their octa-acetates and fused with p-nitrophenol to afford the a-aryl glycosides, and methyl 3-0-ot-D-mannopyranosyl-o -D-mannopyranoside was made via the 4,6-0-benzylidene acetal.Standard reactions applied to the dianhydride (29) afforded means of obtaining the unusual 3-0-methyl-(3-D-idopyranosyl-D-glucose (30) as well as the 3 -deoxy analogue.  

Considerable attention has been given to deoxydisaccharides, mainly because of their biological significance. Benzyl 2,3-dideoxy i3-D-. / cero-pentopyranoside gave compound (36) by appropriate glycosylation, but most attention has 

Considerable attention has been given to amino-sugar disaccharides. The 2-azido-2-deoxyglycosyl chloride procedure has been applied to obtain 2-amino-2-deoxy-a-D-glucopyranosyl a-D-glucopyranoside (trehalosamine)/ and the 2-deoxy-2-phthalamidoglycosyl bromide method to produce 6-0-(2-acetamido- 

Synthesis of Disaccharides and their Derivatives.—Approaches to the synthesis of sucrose and related disaccharides have been discussed in a short review.  

An important development in the synthesis of 1,2-cis-related disaccharides has involved the use of the imidate (40), which forms in high yield when 2,3,4,6-tetra-O-benzyl-a-D-glucopyranosyl chloride is treated with N-methylacetamide in the 

An efficient and general method for the synthesis of 1,2-rrans-related disaccharide derivatives consists of treating an acetylated glycosyl halide with a sugar derivative 

Klemer, Forsch. Landes Nordrhein-Westfalen, 1975, 2507 (Chem. Abs., 1977,87, 184 785k). 

Pougny, J.-C Jacquinet, M. Nassr, D. Duchet, M.-L. Milat, and P. Sinay, J. Amer. Chem. Soc., 

Synthesis of Disaccharides and their Derivatives.—K method has been devised for the preparation of alkyl a-glycosides of reducing disaccharides. Conversion of the peracetylglycosyl bromides to the j3-iV,JV-dialkyldithiocarba-mates was followed by deacetylation and treatment with the alcohol (methanol and benzyl alcohol were used) in the presence of mercury(ii) chloride and cadmium carbonate. Good yields of products containing mainly a-glycosides were obtained from cellobiose, lactose, and maltose.  

In the L-rhamnose series, benzyl 2,3-O-isopropylidene-a-L-rhamnopyrano-side has been used in a synthesis of muricatin B (15), a component of resins of the Convolvulaceae, establishing the nature of the anomeric bonding in the 

A high yield of 1,4-jS-linked product was obtained when methyl 2,3-anhydro-j3-D-ribopyranoside was condensed with 3,4-di-0-acetyl-2-0-benzyl-a-D-xylopyranosyl bromide, and use of tri-O-acetyl-a-D-xylopyranosyl bromide afforded the related product which, on base-catalysed hydrolysis, gave the methyl jS-xylobioside. Several 2-0-glycosyl-D-arabinoses have been prepared by glycosylation of benzyl 3,4-0-isopropylidene-j8-D-arabinopyranoside, and from benzyl 2-0-j3-D-glucopyranosyl-jS-D-arabinoside the aldobiuronic acid was produced.  

Laffite, A. M. Nguyen Phnoc Du, F. Winternitz, R. Wylde, and F. Pratviol-Sosa, 

4- di-0-benzyl-2-deoxy-a-D-glucopyranoside gave, after deprotection, the 1,6-linked isomer of di-A -acetyl chitobiose. A similar attempt to prepare the 

4 Synthesis of Disaccharides and Their Derivatives. - 1.4.1 General. Much material in Section 1.1.1 (Methods of synthesis of glycosides) is also relevant to the methods developed for the synthesis of disaccharides. 

Reduction of glycosylidene acetals, made by condensing aldono-6- 

Methyl p-D-galactopyranoside, activated with dibutyltin oxide and treated with tetra-O-pivaloyl-a-D-glucopyranosyl bromide, gave the 6-p-linked product in 72% yield. In this work the term open glycosylation is used to imply an unprotected acceptor strategy. Related work with the glucuronic acid analogue as donor is reported in Section 1.4.8. 

5 Galactosyl Disaccharides. a-D-Gal-(l- 3)-D-Gal was made following galactosylation of 1,2 5,6-di-O-cyclohexylidene-D-galactofuranose with 

Lactosylsphingolipids have been prepared as have several p-lactosides with carboranyl residues within the aglycons. Octaacetyllactose is a donor for the synthesis of several a, (o-diol lactosides and bislactosides.  

4 Synthesis of Disaccharides and their Derivatives.- In the area of non-reducing disaccharides Barrett s very elegant synthesis of sucrose, which depends on an intramolecular redox cyclization process, has been published in detail. See Vol. 24, p. 29 for a preliminary report. Enzymic transfer from UDP-Gal can be used to obtain (3-d-galactopyranosyl 3-acetamido-3-deoxy-(S-D-xylopyranoside.  

Reagents i, Tebbe reagent ii, methyl tribenzylglucoside, MeCN, BF-, Et,0 iii, MeCN. TMSOTf 

Whereas glycosylations of methyl 4,6-O-benzylidene-a-D-altropyranoside with tetra-O-benzyl-a-D-glucopyranosyl bromide or trichloroacetimidate give mainly the p-(l- 3)-linked disaccharide, the corresponding diazirine reacts mainly at 0-2. A rationalization is provided.  

Considerable attention has been paid to the use of enzymes for galactosylation purposes. The procedure has been used to make a-(1 3)-linked galactobiose derivatives  

8-(Methoxycarbonyl)octyl glycosides have been produced for a range of disaccharides 

2 Synthesis of Disaccharides and Their Derivatives.- Several syntheses of disaccharide derivatives have been described in papers noted in the previous section - particularly in those which refer to new methods of glycoside bond formation other related work appears in papers covered in Chapter h. In the following section compounds are dealt with according to the natures of their non-reducing portions. 

Self condensation of 2,3,, 6-tetra- -benzyl-l-0-trimethylsilyl-a,3-D-glucose with trimethylsllyl trlflate as catalyst gave a 

Five disaccharides and two trisaccharides were isolated following treatment of methyl 4,6-0-benzylidene-a-D-glucoside with tetra-0-acetyl-a-D-glucopyranosyl bromide the main products were 2- and 3-linked compounds but some reaction involved substitution at 

Reaction of D-glucose in DMF containing hydrogen chloride gave several disaccharides as well as l,6-anhydro-3-D-gluco- 

Hydrothermolysis of cellobiose between 180 and 250°C is independent of pH in the range 3-7 the disaccharide is destroyed 8 times faster than is D-glucose, therefore the latter sugar is the 

In the field of non-reducing disaccharides trehalose has been converted into the hexabenzoate having free hydroxyl groups at both 4-positions and thereby, by 

Two molecules of a,a-trehalose have been linked into a macrocycle by way of two thiourea bridges involving the C-6 positions. 

2 of the donor.Other workers however have used the phthalic acid linkage and from diester 29 they prepared P-3-linked glucobiosides achieving 65-80% efficiencies for the cyclizations. 

Hashimoto and co-workers have shown that glycopyranosyl diethyl phosphite, with such participating groups as benzoyloxy or phthalimido at C-2 and 

Disaccharides ending in pentose units include a fully substituted 2-0-a-D-ribofuranosyl-L-rhamnose derivative produced from a glucosyl acetate or glycosyl trichloroacetimidate. 2,3,5-T ri-O-benzoyl-a-L-arabinofuranosyl chloride 

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Synthesis of Disaccharides and Their Derivatives.- Reference is made to the synthesis of disaccharides from thloglycosldes in Section 2 of this Chapter. In the area of non-reducing di-saccharides, a set of sucrose derivatives have been prepared by enzymic methods as follows 1) l -azldo-l -deoxysucrose from 1-azido-l-deoxy-D-fructose and UDPG with a sucrose synthetase, li)... 

Synthesis of Disaccharides and their Derivatives.-Remarkab]y little appears to have been published in 1991 on the chemistiy of non-reducing disaccharides. However, the transformation of [l- -D-glucose to [1,1- CJ-D-trehalose in vivo within the cockroach GtyUodes sifflbitus has been monitored 1 -n.m.r. methods. ... 

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