— 175 — 



a hydrocarbon C 8 H 14 (b. p. 136 to 137 , d 2 oo 0,817, n D 1,4581), 

 which must consist chiefly of a compound of the formula 



C H 9 — C H 2 v /C H 3 



CH 2 -CH/ X CH 3 



as it yields pentanone 1 ) on oxidation. 



When treated with alcoholic sulphuric acid, it is converted into 

 the isomeric hydrocarbon 



C H — CH \ z C H„ 



i 2 V-ch/ 3 



ch 2 -ch/ x ch 3 



from which a solid nitrosochloride was obtained, whereas the former 

 only yielded an oily product. 



4. The constitution of 1,4-methyl cyclohexene acetic acid 

 of the m. p. 42 to 43 02 ) which had already been produced before, 

 could be ascertained by oxidation into methylcyclohexanone as 



CH q — < > = CH.COOH 



The saturated 1,4-methyl cyclohexyl acetic acid (m. p. 63 to 65 ) 

 was obtained like the above-mentioned cyclohexyl acetic acid. 



5. Compounds of menthone. Methyl ester of menthol 

 acetic acid was obtained from menthone, bromoacetic ester, and 

 zinc; m. p. 32 to 33 ; b. p. 136 to 137 (10 mm. pressure). Menthol 

 acetic acid (m. p. 82 to 83 , b. p. 193 to 197 (11 mm. pressure). 

 On producing from this acid menthene acetic acid, by abstracting water 

 by means of potassium bisulphate, there is formed as a by-product 

 the y-lactone C 12 H 20 O 2 (b. p. 300 to 305 , d 1,015, n D22 o 1,4781; 

 lsevorotatory) of the following constitution: — 



y C H 9 — C H 2 V 



CH 3 — CH< >C~CH(CH 3 ) 0) 



I \ 



CH 2 COO 



which on treatment with glacial acetic and hydriodic acids is converted 

 into an isomeric dextrorotatory solid lactone of the m. p. 88 to 89 . 

 Menthyl acetic acid was produced from bromomenthyl acetic ester 

 by reduction and subsequent saponification, analogous to cyclohexyl 

 acetic acid (b. p. 166 to 170 , at 1 1 mm. pressure). 



*) According to Wallach, the semicarbazone of pentanone melts at 205 to 

 206 if heated slowly, and at 212 to 213 if heated rapidly. 



2 ) Liebig's Annalen 347 (1906), 345; Report October 1906, 115. 



