Of the monatomic alcohols of the saturated or methane series but few representatives have thus far been found in volatile oils. In the free state they are found but rarely and then only the lower homologues; more commonly, however, combined with fatty acids. The occurrence of both free alcohol and free acid may in most instances be attributed to the saponification of esters during the process of distillation. If the material to be distilled contains carbohydrates, it may occur that the presence of free alcohols is due to fermentation previous to the distillation. Thus, e.g. ethyl alcohol has been observed in the distillate of rose petals that had been bulked for a short time only.

The methods of preparation of these alcohols are those commonly in vogue. In factory practice, volatile oils containing esters, particularly of the higher members, are used as first materials. Very serviceable is also the method of Bouveault and Blanc,1) according to which primary alcohols are obtained upon reduction of the esters of the respective acids by means of sodium and alcohol.

With the increase in the number of carbon atoms, the properties of the aliphatic alcohols undergo material change. Hence, so far as seemed necessary, attention is directed thereto.

The individual alcohols can be identified by means of their constants, also by their oxidation products. As specially characteristic derivatives, the phenylurethanes should be mentioned. These are obtained by mixing equimolecular parts of phenylIso-cyanate and the alcohol in question. Upon standing of the mixture, the urethane separates in crystalline form.

1) G. I. P. 164294. Comp. also Compt. rend. 136 (1903), 1676; 137 (1903), 60.

Methyl alcohol, CH3OH, occurs frequently among the products of distillation of plant material with water vapors. On account of its ready solubility in water it is frequently found in the aqueous distillate only, together with furfurol and diacetyl. It is assumed that these three substances result as decomposition products of the cellulose of the crude material during the process of distillation. Up to the present time, methyl alcohol has been found in the aqueous distillate of the oils of cypress, savin, vetiver, and orris, of the oils from the leaves of Indigofera galegoides, the leaves from the Guatamala indigo plant, coca leaves, sappan leaves, also in the aqueous distillates from the West-Indian sandalwood oil, tea oil, oil of cloves, oil of Eucalyptus amygdalina, bay oil, pastinaca oil, garden chervil oil, the oils of Heracleum Sphondylium, and H. giganteum, also of ageratum oil. In addition it has been found as myristic ester in orris oil, as benzoic ester in the oils of tuberose (?) and ylang-ylang, as cinnamic ester in the oil from the root of Alpinia malaccensis and watara oil, as salicylic ester in the oil from tuberose pomade, birch bark oil, cananga oil, oil of rue, oil of cassie flowers, tea oil and wintergreen oil, as ester of methyl anthranilic acid in mandarin oil and as anthranilic ester in the oils of neroli and jasmin.

Methyl alcohol can be identified by its boiling point 64°, its density 0,810 at 15° and chemically by its conversion into methyl iodide and neutral oxalate which melts at 54°.

Ethyl alcohol, C2H5OH. As normal constituent of volatile oils, ethyl alcohol has been observed only in a few instances: thus in the first fraction of the oils of Indigofera and of the fruit of Morinda citrifolia, also in the aqueous distillate of Eucalyptus amygdalina, of chevril oil, pastinaca, and Heracleum giganteum. Its occurrence in the distillate of rose petals that have undergone fermentation has already been mentioned. As ester it occurs as butyrate in the oils of Heracleum Sphondylium and H. giganteum, as caprinate in cognac oil, and as cinnamate in storax oil and kaempferia oil.

As one of the most common adulterants of volatile oils, alcohol plays an important role.

It is identified by means of its constants (b. p. 78°; d15o0,794) also by its conversion into either ethyl iodide or iodoform.

n-Butyl alcohol, CH3(CH2)2CH2OH, occurs as ester in Roman chamomile oil. At 20° its density is 0,810 and it boils at 117°. Its phenyl urethane melts between 55 and 56°.2)

CH3 Isobutyl alcohol, /CHCH2OH, is contained, accorCH3 ding to H. G. Smith, in the aqueous distillate of Eucalyptus amygdalina. It boils at 108,4°; sp. gr. 0,8003 at 18°. Its phenyl urethane melts at 80o.1)

CH3 \soamyl alcohol, >CHCH2CH2OH, occurs as such

CH3 in the oils of Eucalyptus Globulus, E. amygdalina, in geranium oil from Reunion,2) lavender oil and French peppermint oil. As ester it occurs in the oils of Eucalyptus Globulus, E. aggregata, in Roman chamomile oil and in cognac oil.

It is readily recognized by its irritating odor, boiling point 131°, its phenyl urethane melting at 52 to 53° and by its oxidation to isovaleric aldehyde and isovalerianic acid.

n-Hexyl alcohol, CH3(CH2)4CH2OH, occurs as ester in the oil of male fern and in the oils of Heracleum Sphondylium and H. giganteum. It boils at 157° and has a specific gravity of 0,8204 at 20°. Upon oxydation it yields capronic acid b. p. 205°.

Active hexyl alcohol (B,B-methyl ethyl propyl alcohol)


>CHCH2CH20H, occurs as ester of angelic acid in Roman chamomile oil. It is dextrogyrate, [a]D + 8,2C; dl50 0,829o; b. p. 154°. Chromic acid mixture oxidizes it to active capronic acid boiling between 196 to 198°.

1) Blaise, Bull. Soc. chim. III. 29 (1903), 327.

2) It has not been definitely established whether this is the common isoamyl alcohol or not.

Heptyl alcohol. Of the heptyl alcohols, the methyl-n-amyl carbinol,Aliphatic Alcohols 124 has been found in oil of cloves by Masson.1) He enumerates the following constants: b. p. 157 to 158°; d0„0,8344. Upon oxidation with chromic acid mixture it is converted into methyl-n-amyl ketone, the semicarbazone of which melts at 122 to 123° and can be used for identification purposes. For this the pyro-uvic acid ester is likewise suited, the semicarbazone of which melts at 118 to 119°.

n-Octyl alcohol, CH3(CH2)6CH2OH, probably occurs in the free state in the oils of Heracleum Sphondylium and H. gi-ganteum, in which it also occurs as acetate. As propionate (?) it has been found in pastinaca oil, as butyrate in male fern and pastinaca oils, as isovalerate in male fern oil, as capronate, caprinate and laurinate in the oil of H. Sphondylium.

It is identified by means of its constants (b. p. 196 to 197°; d16o 0,8278), also by its oxidation to octylic aldehyde (the B-naphtho-cinchoninic acid of which melts at 234°), or to caprylic acid (m. p. 16,5° and b. p. 232 to 234°).

n-Nonyl alcohol, CH3(CH2)7CH2OH, has been found as ester of caprylic acid in sweet orange oil. Under ordinary pressure it boils at 213,5° and has a rose-like odor somewhat resembling that of citronellol. For the alcohol, purified through the phthalic ester, Stephan2) records the following properties:

B. p. 98 to 101° (12 mm.); d15,0,840; aD + 0°; nD15,1,43582.

Nonyl alcohol can be identified by means of its oxidation products (nonyl aldehyde and pelargonic acid, m. p. 12,5°), also by means of its phenylurethane which melts at 62 to 64°.

1) Compt. rend. 149 (1909), 630.

2) Journ. f. prakt. Chem. II. 62 (1900), 532.

As secondary nonyl alcohol, methyl-n-heptylcarbinol,

Aliphatic Alcohols 125 has been found by Power and Lees1) in an Algerian oil of rue, and by Masson2) in clove oil. Its properties are recorded as follows:

B. p. 198 to 200° (765 mm.); d19o / 16o 0,8273; aD (50 mm.) - 3°44' (Power and Lees); b. p. 195 to 196°; d0„0,8399 (Masson).

It can be identified by its oxidation product, methyl-n-heptyl-ketone and the semicarbazone of the latter (m. p. 118 to 119°). With pyrouvic acid it forms an ester which boils at 126 to 127° (16 mm.), and the semicarbazone of which melts at 117°.

Undecyl alcohol. A secondary undecyl alcohol, methyl-/7-nonyl-carbinolAliphatic Alcohols 126 has also been found in the Algerian oil of rue mentioned above. For the purified alcohol, Power and Lees record the following constants:

B. p. 231 to 233°; aD (25 mm.) - 1°18'.

It is identified by means of its oxidation product, the methyl-n-nonyl ketone, the oxime of which melts at 46°, the semicarbazone at 123 to 124°.

Of unsaturated aliphatic alcohols the hexylene alcohol C6H120 which occurs in the tea leaf oil, and the alcohol C8H160, probably an octylene alcohol, which occurs in Gaultheria oil, may be mentioned as representatives of the lower members of the series. Of much greater interest, however, are the terpene alcohols C10H18O, linalool, geraniol, and nerol; furthermore, the unsaturated chain alcohol C10H20O, citronellol. These occur as such and as esters in volatile oils of which they are important constituents because of their fragrance.

1) Journ. chem. Soc. 81 (1902), 1592.

2) Compt. rend. 149 (1909), 630.