The constituents of an essential oil of rue / by Frederick B. Power and Frederic H. Lees. Methyl beta-methylhexyl ketone / by Frederic H. Lees.

  • Power, Frederick B. (Frederick Belding), 1853-1927
Date:
[1902]
Catalogue details

Licence: In copyright

Credit: The constituents of an essential oil of rue / by Frederick B. Power and Frederic H. Lees. Methyl beta-methylhexyl ketone / by Frederic H. Lees. Source: Wellcome Collection.

    11/16 (page 1593)
    methyl n-heptyl ketone, which had the characteristic odour, distilled at 195—199°, and yielded a semicarbazone melting at 118—119°. The proof was thus afforded that this alcohol is methyl-n-heptylcarbinol. Identification of Methyl-n-nonylcarbinol. The fraction boiling at 220—235° was relatively very small in amount. It was acetylated, as in the case of the alcohol of lower boiling point. The product, on fractionation, distilled principally between 240° and 248°, and was most constant at 245°. Hydrolysis afforded the alcohol, which boiled at 230—235°, and was most constant at 231—233°q it had «D — 1°18' in a 25 mm. tube. This fraction was analysed : 0*0991 gave 0-2793 C02 and 0*1220 H20. C = 76*9; H = 137. 0nH240 requires C = 76*7 ; H = 14‘0 percent. This optically active alcohol afforded, on oxidation with chromic* acid, a ketone, which formed an oxime melting at 46—47°. It was thus identified as methyl-?i-nonylcarbinol. A Blue Oil. It has already been noted that from that portion of the oil used for the identification of the alcohols a fraction was separated, boiling above 250°, which possessed a deep blue colour. It was relatively small in amount, and had a rank, weed-like odour. On redistillation, it passed over between 250° and 320°, but was at no point constant. The liquid was dichroic, the colour, in reflected light, being a deep indigo-blue, and in transmitted light, red. It was sparingly soluble in 70 per cent, alcohol. When dissolved in glacial acetic acid, it gave a reddish- brown colour on the addition of a drop of hydrochloric acid. The presence of a blue oil in an oil of rue has not hitherto been observed. The small amount, and the complex character of this liquid, rendered it impossible to determine its composition. Summary. From the preceding details it will be seen that this essential oil of rue, which was apparently of Algerian origin, contained the following substances : 1. Methyl-n-heptylketone. 2. Methyl-n-nonylketone. 3. Methyl-n-heptylcarbinol. 4. Methyl-n-nonylcarbinol. 5. A blue oil of high and inconstant boiling point.