Cellobiose derivatives, synthesis

A similar synthesis starting from the derivatives of maltose (55), lactose (46), and cellobiose (57) to give the L-asparagine derivatives 56,48, and 58, respectively, was accomplished by Dunstan and Hough.46... 

S. Vonhoff, K. Piens, M. Pipelier, C. Braet, M. Claeyssens, and A. Vasella, Inhibition of cellobiohy-drolases from Trichoderma reesei. Synthesis and evaluation of some glucose-, cellobiose-, and cellotriose-derived hydroximolactams and imidazoles, Helv. Chim. Acta, 82 (1999) 963-980. 

The treatment of cellobial with perbenzoic acid and water leads predominantly to 4-( 8-D-glucopyranosyl)-D-mannose.38 On the other hand, the treatment of hexaacetylcellobial in the same manner leads predominantly to cellobiose, which has been isolated as the octaacetyl derivative. Hexaacetylcellobial has also been made from the synthetically prepared epicellobiose, and the conversion of hexaacetylcellobial to cellobiose has completed the total synthesis of this important sugar.17... 

The synthesis of cellobiose octaacetate by the reaction of the sodium derivative of 1,2,3,6-tetraacetyl-D-glucopyranose with 2,3,4,6-tetraacetyl-a-D-glucopyranosyl bromide has recently been reported. Deacetylation resulted in the formation of cellobiose. 

In the synthesis of n-altrose from D-ribose, first effected by Levene and Jacobs, the only crystalline intermediate was the characteristic calcium D-altronate -3.5 H2O. The sirupy lactone prepared from it was then reduced to n-altrose with sodium amalgam, as mentioned earlier in this review. Calcium n-altronate has been obtained from other sources also, such as the aluminum chloride rearrangement of the acetates of lactose, cellobiose and glucose and subsequent transformation of the neolactose, celtrobiose and altrose derivatives thus produced (see Section... 

Ut. Free. Natl. Acad. Sci. USA 93,12637 (1996). gen. ACS Symp. Ser. 340,1-310 (1987) Barton-Nakanishi 3, 529-598 (review) Fengel Wegener, Wood Cbemistiy, Ultrastructure, Reactions, Berlin de Gruyter 1989 Kennedy et al.. Cellulose and its Derivatives, Chichester Norwood 1985 Kirk-Othmer(4.)5,476-497 6,1023 7,292 8,451 Klemm et al. (eds.). Comprehensive Cellulose Chemistry (2 Vol. Vol. 1 Fundamentals and Analytical Methods Vol. 2 Derivat-ization of Cellulose), Weinheim Wiley-VCH 1998 Methods Biotechnol. 10,57 -69 (1999) (enzymatic synthesis) Nature (London) 311, 165 (1984) (biosynthesis) Nevell et al.. Cellulose Chemistry, Chichester Norwood 1985 "Tappi J. 72 (3), 169 (1989) Ullmann (5.) AS, 377-418 Wilke et al., Chem. Technol. Rev. 218 Enzymatic Nydrolysis of Cellulose, Park Ridge Noyes Data Corp. 1983 Wood, Methods Enzymol. 160/A, San Diego Academic Press 1988 Young etal.. Cellulose, New York Wiley 1986. - Journal Cellulose (Roberts, ed.), London Chapman Hall (since 1994). - [HS 391211.391290 CAS9004-34-6(C.) 528-50-7(cellobiose)]... 

In sucrose the fructose unit exists as a 5-membered ring, but on hydrolysis to invert sugar the fructose separates as a 6-membered ring. Maltose contains two molecules of J-glucose, as does cellobiose (from the hydrolysis of acetyl cellulose) but in a different configuration. The synthesis of sucrose was claimed by Pictet and H. Vogel, but this was doubted a definite synthesis from glucopyranose and fructofuranose derivatives was achieved by Lemieux (1953-6). 

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. ... 

Natural abundance C n.m.r. in H20 has been used to examine the possibility of acyl migration during the synthesis of di- and tri-saccharides in which a-D-galactopyranose becomes attached to 0-4 in partially acylated galactose units. Expected structures were confirmed, showing that no 6 - 4 acyl migration had occurred. As models for cellobiose and maltose, twenty-one simple derivatives of cyclohexyloxytetrahydropyran have been studied by C and n.m.r. ... 

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