176 PREPARATION OF METHYLATED SUGARS 



ethers. Thus, ethylation of tetramethylmannitol results in the 

 formation of a diethyl-tetramethyl-mannitol, and a tetraethyl- 

 dimeihyl-mannitol has also been prepared from dimethyl- 

 mannitol. 



Mixed ethers of this type are now receiving attention in 

 view of their powerful narcotic properties, and, as the methods 

 available for their preparation are not numerous and are of 

 limited application, several processes for their production 

 have recently been protected (D.R.P., 226454). By the pro- 

 cess now described it should be possible to prepare mixed 

 ethers of considerable complexity such as dimethyl-diethyl- 

 dipropyl hexitols, in which the relative positions of the three 

 types of alkyloxy groups could be varied, according to the 

 order in which the alkylations were effected. 



Although several workers have contributed the experi- 

 mental data necessary for this paper, special acknowledgement 

 is due to Mr. J. P. Scott, M.A., B.Sc. (Carnegie Fellow), who 

 investigated the partially methylated glucoses now described 

 for the first time. The section of the paper dealing with 

 ethers of polyhydric alcohols is based on results obtained by 

 Miss B. M. Paterson, B.Sc. (Carnegie Scholar). 



It should also be stated that all necessary references to 

 original papers on the alkylation of the sugars will be found in 

 the bibliography appended to Mr. Young's contribution to 

 this volume. 



JAMES COLQTJHOUN IRVINE 



