Cellobiose preparation

Cellobiose was prepared first by Skraup and Konig by the saponification of the octaacetate with alcoholic potassium hydroxide, and the method was improved by Pringsheim and Merkatz.3 Aqueous barium hydroxide also has been employed for the purpose, and methyl alcoholic ammonia has been used extensively for the hydrolysis of carbohydrate acetates. The method of catalytic hydrolysis with a small quantity of sodium methylate was introduced by Zemplen,i who considered the action to be due to the addition of the reagent to the ester-carbonyl groups of the sugar acetate and the decomposition of the addition compound by reaction with alcohol. The present procedure, reported by Zemplen, Gerecs, and Hadacsy, is a considerable improvement over the original method (see Note 2). 

The preparation of a-cellobiose octaacetate by the acetolysis of cellulose was discovered by Franchimont, and the process has been studied carefully by a number of other investi-... 

This osone was first prepared from cellobiose phenylosazone by the benzaldehyde method196 on hydrolysis by emulsin it gave D-glucosone and D-glucose. 

This particular trimethylglucose is unique in that it was separated in crystalline form from the hydrolyzates of the methyl ethers of several naturally-occurring glucose polymers almost two decades before it was synthesized from glucose. These natural sources, which still furnish the most convenient routes for the preparation of 2,3,6-trimethyl-D-glucose, include maltose,124-128 cellobiose,127,128 lactose,122-181 starch,71,182 glycogen,188,184 cellulose,185-187 and lichenin. 188,189 The literature pub-... 

The effects of propagated distortions of the residue are shown in Figure 4, a CA map without contouring that was prepared with the standard driver. The gtgtRR starting model of cellobiose had an energy of 31.4 kcal/mol (its conformation was < ) = 20, - -60). ... 

Other renewable resources sorbitol (I), cellobiose (XXV), etc. can be used in similar ways as starting materials in the preparation of epoxy resins. We are now working on a direct two-step preparation of diepoxy sorbitol derivatives by direct halogenation of the two primary hydroxyl groups with the formation of 1,6-dichloro-1,6-dideoxy-sorbitol, (XXIII), followed by epoxy ring formation (1,2 5,6-dianhydrosorbitol (XXIV) ... 

It is worth pointing out that the ketones derivatives 45a, 45e obtained in one step from D-glucose and D-cellobiose were previously prepared in seven and eight steps, respectively, and low overall yields from commercial 2,3,4,6-tetra-(9-benzyl d-glucopyranose [113]. 

Also prepared during this work were the previously unknown deoxy fluoro cellobioses 28 and 29. 

The most common naturally occurring disaccharides are sucrose (table sugar) and lactose (milk sugar). While sucrose is derived from plants and is prepared commercially from sugar cane and sugar beet, lactose is found in the milk of animals. Other common disaccharides that are produced by breaking down polysaccharides include maltose (obtained from starch) and cellobiose (obtained from cellulose). 

Subsequently, Ordin and Hall (25, 26) found that particulate preparations from oat coleoptiles could use UDP-D-glucose as substrate for polysaccharide formation. Upon degradation of the polysaccharide derived from UDP-D-glucose with impure cellulase, cellobiose, and to a lesser extent a substance identified as a trisaccharide containing mixed / -(1 - 4), / -(1 - 3) glucosyl linkages were obtained. 

---