148 Report of Schimmel $ Co. April /October 1917. 



In connection with the above, a paper published by E. Boedtker and O. M. Halse *) 

 on the Friedel-Crafts reaction attracts interest. They draw attention to the fact that 

 hitherto no use has been found for the ^>-cymene which is formed as a by-product in 

 the manufacture od cellulose, so that it has been the custom to let it escape into the 

 air. The raw material contains about 90 per cent, of pure cymene. It is quite feasible 

 to convert this in cumene or toluerie which are the starting materials for manu- 

 facturing dyes. 



They boiled 150 g. of crude cymene with 1 kg. of benzene and 30 g. of aluminium 

 chloride for 6 hours on the water-bath and thus obtained 52 g. of toluene, 75 g. of 

 cumene, 6 g. of unchanged cymene, and 20 g. of compounds boiling above 200°. In 

 a second experiment, 100 g. of cymene, dissolved in 1 kg. of benzene, produced after 

 6 hour's boiling on the wather-bath in the presence of 20 g. of aluminium chloride 

 41 g. of toluene and 85 g. of cumene, whereas the residue weighed 15 g. In a third 

 experiment, the authors heated 100 g. of cymene, 1 kg. of benzene and 10 g. of aluminium 

 chloride for 8 hours on the water-bath. The results were:— 31 g. of toluene, 67 g. of 

 cumene, whereas 10 g. of cymene remained unchanged. Finally, 90 g. of cymene, 900 g. 

 of benzene and 4.5 g. of aluminium chloride were boiled for 10 hours on the water- 

 bath, whereby 44 g. of toluene and 68 g. of cumene were formed and the residue only 

 consisted of 3 to 4 g. 



Alcohols. 



Mentholglucosides. — /^-Glucosides of terpene alcohols have already been described 

 previously. For instance, E. Fischer and K. Raske 2 ) have prepared the /5-glucosides of 

 menthol and borneol; subsequently J. Hamalainen 3 ) described the /S-glucoside of borneol 

 anew and also obtained a large number of glucosides of other terpene alcohols. Only 

 recently, however, E. Fischer and M. Bergmann 4 ) succeeded in the preparation of the 

 a-glucoside of a terpene alcohol. They have demonstrated that when acetobromo- 

 glucose, phenol, and quinoline are heated together in fairly equal quantities the tetracetyl 

 compound of the already known /S-phenolglucoside and that of the formerly vainly 

 sought-for a-compound are produced. This method can be applied to the hydroaromatic 

 alcohols, for instance to menthol, and by this means the preparation of the hitherto 

 unknown a-mentholglucoside has been realized in a very simple manner. A closer 

 investigation of this process has proved that besides the tetracetyl compounds of both 

 the isomeric glucosides also their triacetyl derivatives are produced which can be 

 separated in a pure state by suitable crystallization methods. Apparently, the process 

 of their formation is inseparable from the splitting off of acetyl from the acetobromo- 

 glucose, although the work was always undertaken with materials which were as dry 

 as possible; hence the splitting-off of these acetates taking place so readily can be 

 easily explained. This secondary reaction can even proceed still further, in fact to 

 the formation of di- and mono-acetates of the corresponding glucosides. This circum- 

 stance may cause considerable loss, but the damage can easily be made good by 

 means of reacetylation with pyridine and acetic anhydride. 



a- and ^-Menthol glucoside behave in the same manner which characterizes this 

 class of compounds towards yeast enzymes and emulsin, or rather as one says nowadays 

 towards «- and /?-glucosidase. There is also a difference between them in the same 

 sense as between «- and /S-methylglucoside, but quantitatively it is much less great. 



!) Bull. Soc. chim. IV. 19 (1916), 444. — s ) Bert. Berichte 42 (1909), 1465; Report October 1909, 178. - 

 3 ) Chem. Zentralbl. 1913, I. 1604, 1925, 1932; 1913, II. 869; Report October 1913, 138. — *) Berl. Berichte 50 

 (1917), 711. Comp. also E. Fischer u. L. v. Mechel, ibidem 49 (1919), 2813. 



