412 RECORD OF SCIENCE FOR 1886. 



Synthesis of Conine, by A. Ladenburg.— Conine, the volatile alkaloid 

 which forms the poisonous principle of hemlock {conium maculatum), 

 was discovered in 1827 by Giesecke, but was first obtained in a pure 

 state in 1831 by Geiger. It has been often studied by chemists, nota- 

 bly by Ortigosa, Blyth, Wertheim, and Kekule and von Planta; the 

 two latter gave it the formula CsHisN, but it is now known to be OsHn]^'. 

 It forms a colorless, oily liquid of pungent odor, specific gravity = 0.89 ; 

 boiling point 166^ to 168o It is easily soluble in alcohol and ether, 

 sparingly in water, and forms crystalline deliquescent salts. It is an 

 active poison. This natural alkaloid has been formed synthetically by 

 Ladenburgiuthe manner to be described, Hugo Schifl', in 1871, thought 

 be had effected this synthesis by the action of alcoholic ammonia on 

 normal butyric aldehyde and subjecting the product to dry distillation, 

 but the base thus obtained proved to be paraconine, an isomeric form. 



Ladenburg's researches on the pyridine bases had already yielded 

 him interesting results. The synthesis of piperidine was noted in our 

 report for the year 1884. On the 25th of February he read a paper be- 

 fore the German Chemical Society entitled " Experiments on the Syn- 

 thesis of Conine," in which he announced the preparation of a base 

 very closely resembling this alkaloid, and in October he presented de- 

 tails of this remarkably interesting synthesis, and proofs of the iden- 

 tity of the artificial and natural ^^ubstances. The process is as follows : 

 Paraldehyde and «-i)icoliue are heated for ten hours in closed tubes 

 to a temperature of 250° to 260°. The allylpyridine thus obtained was 

 separated from the unchanged picoliue, purified and fractioned until it 

 distilled at 187°. 5 to 192°.5. The exact nature of this body was care- 

 fully established by many tests. The a allylpyridine was then sub- 

 mitted in alcoholic solution to the reducing action of sodium, whereby 

 a-propylpiperidiue was obtained. The hydrochloride of this base, 

 when purified, melted at 203<=^ to 205°, and crystallized in silky-white 

 needles. 



The base separated from this salt boiled at 160° to 167° and proved 

 to have the greatest resemblance to conine. After a very careful study 

 of its toxic and optical properties the author satisfied himself of the 

 absolute identity of this dextro — o'-propylpiperidine and conine, 

 C3H7. C5H10. HN. (Ber. d. chem. Ges., xix, 439 and 2578.) 



New Synthesis of an Inactive Borneol, by J. Bout-hardat and J. La- 

 fout. — Berthelot accomplished the synthesis of the camphor of Borneo 

 by treating camphor with potassium alcoholate, and Baubigny by the 

 direct addition of hydrogen. The authors effect the transformation of 

 terebeue,or inactive camphene, CioHje, through the medium of an organic 

 acid into an ether of borneol, which by saponification yields a borneol 

 having no influence on polarized light. With the exception of its in- 

 active optical properties, the new body is identical with borneol. 

 (Oomptes Reudus, cii, 171.) 



