— 133 — 



(semicarbazone, m. p. 224 ; oxime, m.p. 169 to 170 ; a-cyanodihydro- 

 carvone dibromide, Wdis m alcoholic solution -j- 29,0°; m. p. 146 

 to 147 °; /? - cyanodihy drocarvone dibromide, Hdis m alcoholic 

 solution -|- 6,o°; m.p. 91 to 92 ; chlorocyanodipentene [by the action 

 of phosphorus pentachloride and heating the reaction -product with 

 quinoline], C 11 H 14 NC1, b. p. 268 to 270 [ord. pressure]). By hydro- 

 lysing cyanodihy drocarvone there are formed, according to A. Lap- 

 worth 1 ), two stereo - isomeric carboxylic acids: 



• CO C H 2 v /, C H 2 



CH 3 .CH( )CH.C( 



\CH(COOH).CH/ X CH 3 



The a -acid, m. p. 97 to 98 °, predominates when the hydrolysis is 

 incomplete; it can best be purified by recrystallisation from ethyl 

 formiate; Mr> -(-49,9° (in ethyl acetate). This acid has the pro- 

 perties of an unsaturated keto acid, its semicarbazone becomes 

 brown at 2 1 o°, and melts with decomposition at 218 to 221 ; the 

 oxime softens at 180 , then becomes brown, and melts with evolution 

 of gas at 193 to 1 94 . — The /?-acid which is formed on complete 

 hydrolysis, melts at 142 to 143 ; 1«]d -{-28,8° ( m etn y* acetate ); i ts 

 semicarbazone melts with decomposition at 235 to 236 °. — The 

 oxidation of both acids in ice-cold soda solution with 1 per cent, 

 permanganate yields a compound of the gross formula C u H 16 4 ; 

 m.p. 149 to 15 1°. From the neutralised /?-keto acid and hydrocyanic 

 acid, there originated a cyanohydrin CO OH • C 10 H 15 (OH)CN, m. p. 

 188 to 190 . Finally the mutual conversibility of the two isomeric 

 dihydrocarvone carboxylic acids was etablished. 



Camphor. We have before us a communication from O. Schmidt 2 ) 

 on the synthetic preparation of camphor from oil of turpentine, a 

 subject which we have repeatedly referred to in our Reports 3 ). The 

 author produced camphor on the one hand from solid pinene hydro- 

 chloride by conversion of the latter into camphene, esterification and 

 saponification of the camphene to isobornyl , ester or isoborneol, and 

 oxidation of the latter to camphor. On the other hand he boiled 

 turpentine oil with o-chlorobenzoic acid (in a manner analogous to 

 v. Hey den's withdrawn German patent application). The first method 

 gave a yield of camphor of 24,4 °/ = 2i,g°/ theoretically, the second 

 method yielded 28 °/ = 25,1 °/ theoretically. Of terpenes there were 

 regenerated 42,3 and 53,0 °/ respectively. Whether the losses, which 

 occur when such small quantities as ioog. turpentine oil are worked 

 off, can be avoided, is a matter which requires confirmation. Owing 



*) Journ. chem. Soc. 89 (1906), 945. 



2 ) Chem. Ind. 29 (1906), 241. 



3 ) Reports April 1903, 15, 85; October 1904, 123; April 1905, 117. 



