ah clei iat fe) 
84 | REPORT OF SCHIMMEL § Co. OCTOBER 1914/ APRIL 1915. 
way, in that the double linking is preserved, whereas a neighbouring methylene group — 
is attacked. The autooxidation of limonene goes on in the same manner, as the same 
authors have recently discovered’). In this case too not the double linking, but a 
neighbouring methylene group is attacked, under the formation of the still unknown 
alcohol carveol and the ketone carvone. = 
CH CH 
Ge Sa i CH; OC | ee CH: 
C:(CHs)2 + O. = H,0O + Ba 
Bey 
C . CH; C sf CH; 
a-Pinene. Verbenone. 
AC. [eile EN a ) HC. Cie 
C c C 
CH CH CH 
H.C CH, H.C CH. H.C CH, 
| = +16 
| are > 
| : 2 
Acs: ce HO-HC ae CH OC ee 
C-CHs C:-CHs C-CHs 
Limonene. Carveol. Carvone. 
For this investigation a carvene (limonene) was used, which had been purified by 
repeated fractionation over sodium: di50 0,845; a) + 106°. It remained for 21/2 months 
in a losely covered vessel, exposed to the action of the oxygen of the air in the 
presence of a small quantity of water. After this time, the feebly acid reaction product 
was neutralized with soda solution, and the volatile constituents were distilled off with 
steam. It resulted that from 400 g. of carvene 270 g. of volatile products had formed. 
Through treatment with sulphite solution, 7-carvone was isolated. The ketone which, 
after having been separated from the hydrosulphonic acid solution, had been purified 
by converting it into its semicarbazone (m. p. 154 to 155°), boiled at 230°; dis0 0,965. 
The part of the oil, which did not react with sulphite, was treated with benzoyl 
chloride and pyridine, and the alcohol recovered from the benzoate was purified by 
way of the phenylurethane (m. p. 94 to 95°). In this way pure i-carveol, CioHigO, a 
viscid oil of a not very pleasant odour, resembling that of dihydrocarveol, was obtained. 
b. p. 108 to 110° (11 mm.); 226 to 227° (751 mm.); dis0 0,9578; ap — 0; Npiso 1,4961. 
Genvresse’s limonenol?) is most likely only an impure carveol. Genvresse indicates 
the following constants for the product: b. p. 135° (15 mm.); dis0 0,9669; e170 + 19°21’; 
Np 1,497. Otherwise only one derivative of carveol was known, carveol methyl ether, 
which Wallach?) obtained from limonene tetrabromide by treating with alkalis and 
heating with sodium. 
Blumann and Zeitschel ascertained the following properties for the acetate of 
i-carveol: m. p. 115 to 116° (10 mm.); diso 0,9755. The ester has a pronounced spear- _ 
mint odour. The phthalate melts between 136 and 137°. By oxidation with chromic a 
acid in glacial acetic acid solution, i-carveol is converted into 7-carvone. The dehydration 
1) Berl. Berichte 47 (1914),'2623. — *) Compt. rend. 182 (1901), 414; Report April 1901, 66. — Liebigs ‘ 
Annalen 281 (1894), 127; Report October 1894, 12. , E aly, 
