— 114 



e 



from Wallach's publication on the subject 1 ), ascaridol, when suspended 

 in water in the presence of colloidal palladium absorbs 4 atoms hydrogen 

 with unexampled rapidity, in such a manner that it is necessary to regulate 

 the supply of hydrogen in order to obviate the heat generated during the 

 process becoming too powerful. The reaction gives rise to two bodies 

 which are easily separated from each other. One is an oil which easily 

 volatilises with steam; the other a less readily volatilisable, solid 

 body. The latter is most readily isolated by extracting the residue with 

 chloroform after the bulk of the volatilisable body has passed over. The 

 solid reduction-product constitutes a new terpin: 1,4-terpin (terpinene 

 terpin), and occurs in the form of bold prisms, m. p. 116 to 117°. This 

 terpin may occur in two sterically isomerous modifications, of which 

 that melting at 137° was described by Wallach 2 ) a few years ago. The 

 body with m. p. 116 to 117°, therefore, would represent the second modi- 

 fication. The principal product which is formed when the 1,4-terpin is 

 heated with oxalic acid is 1,4-cineol 3 ) (b. p. 172°; d 18 o 0,9010; n Dlgo 1 ,4479), 

 which, when mixed with hydrobromic glacial acetic acid yields terpinene 

 dihydrobromide (m. p. 58 to 59°). When subjected to persistent warming 

 with potassium permanganate the result was not an acid corresponding 

 with cineolic acid, but a sparingly-soluble acid, m. p. 157°, with a smaller 

 oxygen-content. When 1,4-terpin is split up by oxalic acid it yields, 

 in addition to a large proportion of 1,4-cineol, a small proportion of an 

 unsaturated alcohol. This alcohol cannot be obtained in the pure state, 

 but it was possible to identify its oxidation-product. For this purpose 

 the decomposition-product of the terpin, distilled off with steam, was 

 oxidised with 1 p. c. potassium permanganate solution at 0°, and the 

 1,4-cineol which was present blown off with steam. The residue contained 

 a glycerol which, when heated with dilute sulphuric acid, was split up, 

 affording cymene and a ketone, zP-menthenone-3. Thus the presence in 

 the original substance of zl 3 -menthenol-l was proved. Under continued 

 oxidation the two terpinenols of which the existence is possible, yield 

 a,ot'-dihydroxy-«-methyl-a f -isopropyladipic acid, which is easily identifiable 

 by conversion into the dilactone. The author succeeded, in fact, by suitable 

 treatment .of the oxidation-liquors, in isolating a dilactone C10H14O4, 

 m. p. 72°. This affords the proof of the presence of a terpinenol in the 

 reaction-product obtained from the terpin with oxalic acid and identified 

 the terpin itself as a compound of the terpinene series. 



The oil which is formed in addition to terpin during the process of 

 reducing ascaridol contains both saturated and unsaturated constituents. 

 For this reason the body was further reduced in the presence of palladium 

 and the ultimate residue of unsaturated substance removed with potassium 



x ) Nelson's paper appeared when the substance of Wallach's experimental work was concluded. 



2 ) Comp. Report April 1907, 142. 



3 ) Comp. Report April 1908, 185. 



