Messrs Morrell and Crofts, Modes of Formation of Osones. 117 



The maltosone was obtained as an uncrystallisable syrup. 



The yield of maltosone, if small quantities of maltosazone were 

 used, was very good, being 70 °/ of the theoretical amount 

 [E. Fischer, loc. cit.]. We have not been so successful in obtaining 

 so good a yield of maltosone when 20 grams of maltosazone were 

 worked up in one operation. 



The osones of several synthetical disaccharides, galactosido- 

 galactose, glucosidogalactose and galactosidoglucose (melibiose ?) 

 were obtained by this method [E. Fischer, loc. cit.]. The trans- 

 formation of the osazones of the hexoses into osones is not so 

 satisfactory, owing to the insolubility of these osazones in water. 

 The addition of alcohol, although it brings the osazone into solu- 

 tion, does not accelerate the reaction of the osazone with benzalde- 

 hyde, since benzaldehyde hydrazone is also soluble in alcohol. 

 Phenylglucosazone has not been transformed into glucosone by 

 this method, although we have tried heating it with benzaldehyde 

 and alcohol and water under pressure, and also with benzaldehyde 

 and alcohol in a sealed tube to 125° C. Formalin does not trans- 

 form phenylglucosazoDe into glucosone when heated with it in the 

 presence of water. The osazone is undoubtedly attacked by the 

 formalin, but the solid product is of an uninviting appearance, and 

 the filtrate, after it has been shaken with ether and concentrated 

 in a vacuum does not contain glucosone. By means of orthonitro- 

 benzaldehyde glucosazone can be partially transformed into gluco- 

 sone. The change does not occur when the osazone is boiled with 

 water and with sufficient alcohol to keep the orthonitrobenzalde- 

 hyde in solution ; but if orthonitrobenzaldehyde, dissolved in 

 50 °/ alcohol, is heated with glucosazone in a sealed tube to 

 125° G. interaction between the osazone and the aldehyde takes 

 place, and about 20 °/ of the osazone is changed into glucosone. 

 If rhamnosazone is heated with orthonitrobenzaldehyde and alcohol 

 and water in a sealed tube at 125° C. for several hours, a small 

 quantity of rhamnosone, about 6 °/ , is obtained, but if the tempera- 

 ture is raised to 140°, no rhamnosone can be detected. Since 

 glucosone is easily transformed into furfurol on being heated with 

 water to 140° C, it is probable that the rhamnosone is transformed 

 into a methyl furfurol derivative at this temperature. By applying 

 Herzfeld's method to the preparation of rhamnosone from rhamnos- 

 azone, modified by the addition of a small quantity of alcohol in 

 order to bring the osazone into solution, we have obtained a yield of 

 nearly 20 °/ of rhamnosone. 



Rhamnosone is very soluble in ethyl and methylalcohol. From 

 an alcoholic solution acetone or ether precipitate rhamnosone in a 

 syrupy form, but as yet we have been unable to obtain it crystalline. 

 Rhamnosone, prepared by this method, possesses the characteristic 

 properties of the osones ; it reacts readily with substituted hydra- 



