Origin and Production. In order to render palatable the crude expressed cocoa nut oil of Cocos nucifera, L. (family Palmae) it must be deprived of its malodorous constituents, principally fatty acids, and treated with high tension steam. In addition to fatty oil carried over mechanically, the distillate contains a disagreeably smelling volatile oil which has been examined by A. Haller and A. Lassieur2).
Properties. In a 200 mm. tube the oil deviated +0°28'. It contained 0,7 p.c. acids computed as capronic acid, and 12 p.c. alcohols, computed as methylnonyl carbinol, also traces of an aldehyde.
Composition. By treatment with phthalic acid anhydride, the alcohols were separated from the other constituents. This alcohol mixture yielded two fractions: (I) b. p. 190 to 195°, and (II) b. p. 228 to 233°.
Fraction I is a liquid with a strong odor and the following properties: d25/40o0,823; aD + 2°; nD21o 1,4249; mol. refr. 44,8, computed for C9H20O 45,0. The analyses likewise agreed with the formula C9H20O. Upon oxidation with chromic acid mixture, methylheptyl ketone resulted. Hence the alcohol was d-methyl-heptyl carbinol, Ch3ch(OH)C7 H15, the optical antipode of which occurs in oil of rue. The differences in the degree of rotation (methylheptyl carbinol from oil of rue deviates - 7°28') are probably due to inversion caused by the treatment with phthalic acid anhydride.
1) Schreiner, loc. cit
2) Compt. rend. 150 (1910), 1013; 151 (1910), 697.
Fraction II contained an alcohol of the following properties: d23/40o 0,827; aD +1°10'; nD23o 1,4336; mol. refr. 54,1, computed for C11H240 54,2. The analyses suggested the formula C11 H24. Upon oxidation with chromic acid mixture a ketone (m. p. of semicarbazone 120 to 122°) was obtained. Hence the alcohol C11H240 is d-methylnonyl carbinol, Ch3 CH(OH)C9H19, and the semicarbazone, methylnonyl ketone semicarbazone. Of this alcohol the optical antipode (aD - 6° 12') likewise occurs in oil of rue.
Of non-alcoholic constituents the following were identified: methylheptyl ketone (m. p. of semicarbazone 119 to 120°), methyl-n-nonyl ketone (m.p. of oxime 44 to 45°, of semicarbazone 122°), and methylundecyl ketone. Regenerated from its semicarbazone (m.p. 121 to 122°), the latter-named body constitutes a white mass melting at 29°. Its properties agree well with those of the synthetic product (m. p. 28°; b. p. 263°)1).
Haller and Lassieur are of the opinion that the ketones and alcohols found in the volatile oil of the cocoanut result from the action of an enzyme on an unknown substance.