226 



127. Carvone. 



AROMATIC ALDEHYDES AND KETONES [127-128 A. 



[B.] Terpineol [39] gives a nitroso- 

 chloride (Wallach, Ann. 277, 121), 

 which on heating with sodium ethoxide 

 gives ' oxybishydrocarvoxime ' = HO . 

 C 10 H 5 :N.OH. The latter yields i- 

 carvone on heating with dilute sulphuric 

 acid (Ibid. Ber. 28, 1773 > Wallach and 

 Arny, Ann. 291, 342). 



CH 



H 2 C 



HC 



CH 2 



O 



v/.. 



J, 



V 



CH 3 



NATUEAL SOURCES. 



d-Carvone occurs in oil of caraway 

 from Carum car-id (Volckel, Ann. 35, 

 308; 85, 246; Wallach, Ann. 277, 

 107), and in oil of dill from Peucedanum 

 graveolens (Gladstone, Journ. Ch. Soc. 

 25, I ; Beyer, Arch. Pharm. 221, 

 283). 



1- Carvone occurs in oil of spearmint 

 from Mentha aquatica, var. crispa (Ger- 

 many), and from M. viridis, N. America 

 (Gladstone, loc. cit. ; Fliickiger, Ber. 9, 

 473 > Beyer, loc. cit. ; Kremers and 

 Schreiner, Pharm. Rev. 14, 244 ; Wal- 

 lach, Ann. 305, 223 ; in Russian oil, 

 see SchimmeFs Ber. April, 1898; Ch. 

 Centr. 1898, 1, 991), and in oil of 

 kuromoji from the Japanese Lindera 

 sericea (Kwasnik, Ber. 24, 81 ; Arch. 

 Pharm. 230, 265). 



SYNTHETICAL PROCESSES. 



[A.] From dipentene (limonene) [9] 

 by combination with nitrosyl chloride 

 and decomposition with alcoholic potash, 

 whereby the oxime of carvone is pro- 

 duced (Goldschmidt and Ziirrer, Ber. 

 18, 1732; Wallach, Ann. 245, 268). 

 The same nitrosochloride is obtained 

 by mixing d- and 1-limonene nitroso- 

 chlorides (Wallach, Ann. 252, 124; 

 270, 175). 



Or limonene tetrabromide (Wallach, 

 Ann. 227, 280), on heating with methyl 

 alcoholic sodium methoxide, gives brom- 

 carveol methyl ether (Ibid. Ann. 281, 

 129), and this, by the further action of 

 sodium ethoxide in absolute alcohol, 

 yields carveol methyl ether (Ibid. 132). 

 The latter on oxidation with chromic 

 acid in acetic acid solution gives i- 

 carvone. 



128. Fulegone. 



CH, 



CH 



H 2 C 

 H 2 C 



\ 



CH 2 



C:0 



O/ 



C(CH,) a 



NATURAL SOURCES. 



In oil of European pennyroyal from 

 Mentka pulegium (Beckmann and Pleiss- 

 ner, Ann. 262, i ; Bull. Soc. [3] 25, 

 no; Tetry, Ibid. 27, 186), and of N. 

 American wild mint from Mentka cana- 

 densis (Gage, Pharm. Rev. 16, 412). 



Has been found also in oil of Ameri- 

 can pennyroyal from Hedeoma pule- 

 gioides (Habhegger, Am. Journ. Pharm. 

 65, 417), in oil from the mountain 

 mint, Pycnanthemum lanceolatum = 

 T/iymus virginicus (Alden, Pharm. Rev. 

 16, 414), in the oil of Bystropogon 

 origanifolium fromTeneriffe (SchimmePs 

 Ber. Oct. 1902; Ch. Centr. 1902, 2, 

 1208), and in oil of sweet marjoram 

 from Origanum major ana (Genvresse 

 and Chablay, Pharm. Centr. 43, 

 419; Pharm. Journ. 69, 335; Journ. 

 Soc. Ch. Ind. 21, 1347). 



The natural product is d-pulegone. 



SYNTHETICAL PROCESSES. 



[A.] Citronellal [105] on heating 

 with acetic anhydride gives isopulegol 

 [42], and this on oxidation with chromic 

 acid in acetic acid yields isopulegone. 

 The latter is transformed into pulegone 

 by contact with barium hydroxide solu- 

 tion at ordinary temperatures (Tiemann 

 and Schmidt, Ber. 29, 903 ; 30, 29 ; 



