— 207 — 



there occurs a small proportion of a second modification, which was 

 not examined more closely. 



When the acid melting at no to in° is boiled with acetic acid 

 anhydride, there results semicyclic 1,4-methyl-cyclohexane- 

 propionic acid; when it is oxidised with permanganate of po- 

 tassium, 1,4-methyl-cyclohexanone is formed. Dry distillation yields 

 1,4-methyl-cyclohexenethane (b. p. 152 to 153 , d2io 0,810; 



n D2i° i,457i) : 



When subjected to slow dry distillation, the same hydrocarbon 

 yields methyl-cyclohexanol propionic acid, which melts at no 

 to in . This forms a nitrosochloride (m. p. 1 08 to no°, from ether and 

 a little methyl alcohol), which, with pip eridin, yields a nitrol-piperidide, 

 m. p. 127 to 1 2 8°. Treatment with sodium acetate in glacial acetic acid 

 produces the oxime of zl 3 -tetrahydro-p-acetyl-toluene, m. p. 117 . 



By condensing cyclopentanone with bromopropionic ester, cyclo- 

 pentanol propionic ester is obtained. The free acid melts at 

 58 to 59 . When the ester is treated with bisulphate the result is a 

 mixture of cyclopentene propionic acids with isomeric bonds. 

 When the free cyclopentene propionic acid is boiled with acetic an- 

 hydride, semicyclic cyclopentene-propionic acid, m. p. 107 

 to 108 , together with considerable proportions of hydrocarbons, results. 

 Dry distillation yields ethylidene cyclopentane: b. p. 113 to 117°, 

 d2o° 0,8020, n D20° 1,4481, of which the nitrosochloride, when treated 

 with piperidin, yields a nitrol piperidide, m. p no°. When the nitroso- 

 chloride is boiled with acetate of sodium and glacial acetic acid there 

 is obtained from it the oxime of acetyl-cyclopentene, m. p. 90 to 91 

 (from petroleum ether), m. p. of the benzoyl-combination 116 to 117 . 

 When it is boiled with dilute sulphuric acid it yields acetyl-cyclo- 

 pentene, of which the semicarbazone has a m. p. varying from 203 to 

 211 , according whether the heating is done slowly or rapidly. The 

 ketone regenerated from the semicarbazone has a pronounced odour 

 of benzaldehyde, and possesses the following constants: b. p. 173 

 to 1 74°, di 9 o 0,948, n D190 1,4749. 



Besides the above, the isomeric ethyl cyclopentene with cyclic 

 double-bond was formed. This had a b. p. of 107 to no°, d2o° 0,7975, 

 n D20 o 1,4426. 



PIT 



I. (CH 2 ) X / 2 \c(0;H).CHR.CO,H (resp. C0 9 C 2 H,) 

 X CH/ 



/CH..v 



II. (CH,) X < y.CHR.C0 2 H 



x ch/ 



III. (CH 2 ) X / 2 \c = CR.C0 9 H 

 X CH / 



