Chemistry. — “Two ILsomeric Chloro- Tetracetyl-d-Fructoses’”’. By 
Prof. F. M. Jarcer. 
(Communicated at the meeting of June 26, 1920). 
$ 1. Some time ago Dr. D. H. Brauns observed that, when phos- 
phorus pentachloride at low temperatures acts upon B-tetracetyl- 
fructose dissolved in dry chloroform, under differently chosen cireum- 
stances, tvo compounds are formed in the reaction, which both have 
the composition of a chloro-tetracetyl-fructose, but which differ 
considerably in properties. The one isomeride: a-chloro-tetracetyl-d- 
Fructose, melts at 83° C., and has a specific rotation of [el == 
160°,9 (the maximum value measured in chloroform-solution); it is 
produced only, if aluminiumchloride be added to the reaction-mixture 
as a catalyst. Contradictory to what one might perhaps expect 
beforehand from this mode of preparation, this @-derivative appears 
to be unstable to such a degree, that it is decomposed into an impure 
B-tetracetyl-fructose and an acid liquid within twenty-four hours, if 
exposed to the air at room-temperature. Only if preserved in the 
dark in an ice-box at a temperature of O° C,, it appeared possible 
to recrystallize the substance repeatedly from dry ether, if moisture 
be excluded as carefully as possible; even then, however, the decom- 
position mentioned above finally sets in. On the other hand, the other 
isomeride: 3-chloro-tetracetyl-d- fructose, which is produced under the 
same circumstances, if only no catalyst be added to the -mixture, 
appears to be a very stable substance in comparison with the labile 
a-derivative, and may be recrystallized from most of the organic 
solvents, without being changed to any appreciable degree. It melts 
at 108°C., and has, in chloroform-solution, a specific rotation of 
[ei 4502 While the «-compound has an intensely bitter 
taste, the g-derivative tastes only feebly bitter, and it is considerably 
more soluble in most solvents than the a-isomeride. The 8-compound 
is also not absolutely stable: when repeatedly recrystallized from 
absolute alcohol, the formation of ethylacetate can be observed; and 
when solutions in commercial benzine are slowly evaporated at 
18° C., the crystals obtained appear to be slightly coloured pink, 
while the mother-liquid also assumes a gradually increasing violet 
or even brown colour. In comparison with the ¢-compound, however, 
it can be considered to be “stable”; as far as known, these two 
