Online Encyclopedia

C8H

Online Encyclopedia
Originally appearing in Volume V26, Page 651 of the 1911 Encyclopedia Britannica.
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C8H,3~C /O~C2H,4~C0 %0—war,/ — \L). (r) (2) (3) (4) Thus camphor and its oxidation products are to be represented as CH2-CH- CIi2 (a) CH2' CH' CO_H CO2H COzIl ` C(CH3h (r) C(CH3)2 C(CH3)2 CH2'C(CH2)---CO(t), CH2'C(CH2)'CO2H, CHz' C(CHa)'CO2H Camphor, Camphoric acid, Camphoronic acid. Camphor yields three classes of halogen substitution derivatives known respectively as a, and x compounds, the positions being shown in the formula above. The a compounds result by direct substitution, the I4 and r derivatives being formed in an indirect manner. Cyancamphor, C,0Hi30•CN, is formed by passing cyanogen gas into sodium camphor, or by digesting sodium oxymethylene camphor with hydroxylamine hydrochloride (L. Claisen, Ann., 1894, 281, P. 351). rr-Camphor sulphonic acid results from the action of fuming sulphuric acid on camphor (F. S. Kipping and W. J. Pope, Jour. Chem. Soc., 1893, 63, P. 573). Camphoroxime, C,ol-116O:NOH, was first prepared by E. Nageli (Ber., 1883, 16, p. 497). 1-Camphor is formed by the action of nitric acid on l-borneol (fit'. J. Pope and A. W. Harvey, Jour. Chem. Soc., 1901, 79, p. 76)-r-Camphor melts at 178-179° C. (for its preparation see A. Debierne, Comptes rendus, 1899, 128, p. 1110; W. A. Noyes, Amer. Chem. Jour., 1905, 27, p. 430). Camphoric acid. Four optically active and two inactive forms of this acid are known. The most important is the d-form, which is produced by the oxidation of d-camphor with nitric acid. It crystallizes in plates or prisms which melt at 187° C. Potassium permanganate oxidizes it to oxalic acid and Balbiano's acid, C5H1201, together with small quantities of camphanic, camphoronic and trimethyl succinic acids. It yields two series of acid esters, the allo-esters (I), formed by the partial saponification of the neutral esters, and the ortho-esters (2), formed by heating the anhydride with alcohols or sodium alcoholates. CH2' CH • CO211 CH2' CH' CO2R C1CH3)2 C(CH3)2 CH2' C(CH3)' CO2R CH2' C(CH3)' CO2H (r) (2) 1-Camphoric acid results on oxidizing l-borneol or matricaria camphor. It melts at 187° C. r-Camphoric acid is formed on mixing alcoholic solutions of equimolecular quantities of the B-and 1-acids, or by oxidizing i-camphor. It melts at 202-203° C. Camphoronic acid, C91-114O6. From a study of its distillation products J. Bredt (Ber., 1893, 26, p. 3049) concluded that this acid (s) (2) Fenchone, C10H120, is trimethyl - (2 . 7 ) - bicyclo- (I • 2 .2). hepta- none-3. It occurs in d- and 1-forms, the former in oil of fennel and the latter in oil of thuja. It may be obtained from these oils by treating the fraction boiling between 190-195° C. with nitric acid and distilling the product in a current of steam. The fenchones are pleasant-smelling oils which boil at 192-193° C., , and on solidification melt at 5-6° C. They do not combine with sodium bisulphite. They dissolve unchanged in cold concentrated hydrochloric and sulphuric acids, and are very stable; thus the monobromfenchone is only formed by heating the ketone with bromine to Too° C. under pressure (H. Czerny; Ber., 1900, 33,
End of Article: C8H
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