Notes on scientific research. 



117 



broken up in this case. The compound formed is in fact a semicyclic methylene 

 compound, such as the 1:2: 2-trimethyl-3-methylene-c^cfopentane-l-carboxethylate 

 (IV, b. p. 93° [12 mm.]) which was obtained by boiling bromocampholate with an 

 alcoholic solution of sodium ethylate. By reduction of a-campholide with sodium, 

 1 : 2 : 2-trimethy%c?opentane-dimethanol-l : 3 (V, m. p. 130°) was prepared. 



Finally the authors mention a process by means of which they prepared «-camphidone 

 (VI, m. p. 233°) and camphidine (VII, m. p. 182°) from the campholide, respectively the 

 glycol (V) by heating with ammoniacal zinc chloride. These bodies had already been 

 obtained by Tafel and Eckstein 1 ) from the imide of camphoric acid. 



CH, 



CH, 



HC 3 



-CH 



I 



-C- 



I 



c 



CH 3 



CH 3 



(I) a-Campholide. 



CH 2 



I 

 O 



I 

 -CO 



CH 5 



CH S 



CH 



I 

 C- 



I 



CH 2 Br 



CH a 



CH 2 — C(CH 3 ) • COOH 



(II) Bromocampholic acid. 



CH 2 



CH, 



CH 



CH 2 • CH-2 • CeH= 



CH 3 - 



CH 3 



COCH 2 C 6 H 5 



-C 



I 



c— 



I 



CH 3 



(III) 1 :2:2-Trimethyl-3-phenylethyl- 

 ct/ciopentane-1-benzylketone. 



CH S 



CH 2 



CH 2 - 



CH 3 -C— CH, 



I 

 -C 



COOC 2 H 5 



CH 3 



(IV) 1:2: 2-Trimethyl-3-methylene- 

 ei/c£opentane-l -carboxethylate. 



:h s 



CHCH 2 OH 



I 



CH 3 — C-CH 3 



CH 2 - 



(V) 1 :2:2-Trimethyl-cyc?opentane- 

 dimethanol-l:3. 



CH 2 



CHCH 



I 

 CH 3 — C— CH 



C(CH 3 )CH 2 OH CH 



I 

 C(CH 3 )-CO 



(VI) a-Camphidone. 



CH 2 



CH 5 



— CHCH 2 



I 

 CH 3 — C — CH 3 



I 



NH 



C(CH 3 )CH 2 



(VII) Camphidine. 



Glucosides. 



Since the ordinary chemical determinations of dextrose fail in the presence of 

 some other sugars, Em. Bourquelet and M. Bridel 2 ) have worked out a new, biochemical 

 process which is specific only for dextrose. The method is based upon the property 

 of emulsin to form glucosides from dextrose and alcohol, and it allows of determining 

 this kind of sugar qualitatively and quantitatively in the plants. Thus two parts of 

 dextrose, dissolved in 100 parts of methylalcohol (70 per cent), formed in the presence 

 of emulsin about 82 per cent, of methylglucoside. This reaction, which is also reversible, 

 does, however, not proceed further. From the change in the angle of rotation of the 

 solution the quantity of glucoside formed and, further, the desired percentage of 

 dextrose are calculated. By means of this method the authors ascertained that the 

 reducing sugar of juniper berries contains 19.5 per cent, of dextrose, and that the 

 glucoside which Bourquelot and Bridel 3 ) found in Loroglossum hircinum, Rich, consisted 

 partially also of dextrose. 



l ) Berl. Berichte ?A (1901), 3274. — 2 ) Compt. rend. 170 (1920), 631, 



3 ) Cf. Report April 1915, 79. 



