36 



HYDROCARBONS 



[719. 



on heating with dilute sulphuric acid 

 gives, among other products, a small 

 quantity of styrene (Erlenmeyer, Ber. 

 13, 304). 



[J.j From methylphenyl carlinol [58] 

 by conversion into the chloride and 

 heating the latter with pyridine at 130 

 (Klages and Keil, Ber. 36, 1632). 



8. Metastyrene. 

 (C 6 H 6 .CH:CH 2 ) X 



NATURAL SOURCES. 



Occurs in liquid storax (Kowalewsky, 

 Ann. 120, 66), and in Siegburgite, a 

 fossil resin found in sandy concretions 

 over deposits of brown coal at Troisdorf 

 and Siegburg (Klinger and Pitschki, 

 Ber. 17, 2742). 



SYNTHETICAL PROCESS. 



[A.] From styrene [7] by polymerisa- 

 tion through heat (Blyth and Hofmann, 

 Ann. 63, 311; Lemoine, Comp. Rend. 

 126, 530; Kronstein, Ber. 35, 4153) 

 or light (Lemoine, Ibid. 129, 719), by 

 the action of a hot solution of acid 

 sodium sulphite (Miller, Ann. 189, 341) 

 or of strong sulphuric acid (Berthelot, 

 Bull. Soc. Q, 296). 



9. Dipentene; Inactive Limonene; 

 Cajeputeiie ; Terpilene ; Oinene ; Di- 

 isoprene ; Isoterebenthene ; Caout- 

 chene. 



CH, 



A 



HC CH, 



11-'.' OH.2 



3H 



H S C . C : CH 2 



NATURAL SOURCES. 



Occurs in Russian and Swedish tur- 

 pentine oil (Bertram and Walbaum, Arch. 

 Pharm. 231, 290; Wallach, Ann. 230, 

 244 ; 246) ; in camphor oil from Cinna- 

 momum camphora (Lallemand, Ann. 114, 



196; Wallach, Ann. 227, 296); prob- 

 ably in oil of cascarilla from the bark 

 of Crotoneluteria, Bahamas (Briihl, Ber. 

 21, 152; compare Thoms,Ch.Centr. 1900, 

 2, 574) ; in kuromoji oil from the 

 leaves of Lindera fericia, Japan (Kwas- 

 nick, Ber. 24, 81) ; in oil of elemi resin 

 from Canarium sp. ? (Wallach, Ann. 

 246, 233; 252, 102), and in oil of 

 Canadian golden-rod from Solidago 

 cawar/i??ms(SchimmeFsBer. April, 1897). 



Dipentene is contained also in the oil 

 of lemon-grass from the Indian Andro- 

 pogon citratus (Stiehl, Journ. pr. Ch. 

 58, 51 ; Tiemann, Ber. 32, 834, on 

 authority of Bertram) ; in oil of berga- 

 mot (Charabot, Comp. Rend. 129, 728) ; 

 in oil of pine-needle (Bertram and 

 Walbaum, Arch. Pharm. 231, 296 ; 

 Wallach, Ann. 227, 287); in Ceylon 

 citronella oil from Andropogon nardus 

 and vars. (Bertram and Walbaum, Journ. 

 pr. Ch. [2] 49, 16; SchimmePs Ber. 

 Oct. 1899); in small quantity in East 

 Indian geranium or palmarosa oil from 

 Andropogon schcenanthus (Gildemeister 

 and Hoffmann, p. 364) ; possibly in oil 

 of bay from Pimento, acris (Mittmann, 

 Arch. Pharm. 227, 529 ; compare Power 

 and Kleber, Pharm. Rund. 13, 60) ; as 

 ' terpinol ' (a mixture) in oil from the 

 Californian bay, Umbellularia californica 

 (Stillmann, Ber. 13, 630 ; Wallach, 

 Ann. 230, 251); in oil of cubebs from 

 Piper cubeba (Wallach, Ann. 238, 78) ; 

 possibly in oil of black pepper from Piper 

 nigrum (Wallach, Ann. 287, 372) ; 

 possibly in oil of Ceylon cardamom from 

 Elettaria cardamomum^&v. (Weber, Ann. 

 238, 98) ; and in oil of mace or nutmeg 

 from Myristica fragrans (Semmler, Ber. 

 23, 1803; 24, 3818). 



Dipentene is contained in oil of 

 Massoia bark (Schimmel's Ber. Oct. 

 1888; Wallach, Ann. 268,340; Arch. 

 Pharm. 229, 116) ; possibly in oil of 

 lime leaves from Citrus limetta (Watts, 

 Trans. Ch. Soc. 49, 316); in oil of 

 fennel from Fceniculum vnlgare (Schim- 

 meFs Ber. April, 1890) ; in oil of 

 myrtle from Myrtus communis (Ibid. 

 April, 1889) ; in kesso oil from the root 

 of Japanese valerian, Valeriana officinalis 

 var. angustifolia ; possibly derived from 

 pinene or terpineol by the action of acid 



