Part 7

Assuming that the stearoptene obtained was borneol, a determination of the constants of the stearopteneless oil was made. The acid number remained practically the same, being 2.3; the ester number differed only very slightly, being 24.7; but the acetylization value obtained was only 132, which corresponded to but 40 per cent of total borneol. This is in strict conformity with the assumption, which seemed to be sufficiently proved, that the stearoptene separated from the oil by freezing was borneol. The stearopteneless oil was nearly 3 per cent poorer in borneol than the original oil, as shown above. It is to be remembered that 3 per cent of crystalline borneol was removed by freezing the original oil, hence the lowering of the borneol content of the stearopteneless oil.

FREE ACIDS.

The determination of the free acids was accomplished by repeatedly shaking a portion of the original oil with a 10 per cent sodium carbonate solution. After removing the adhering oil from the alkaline liquid by shaking with ether, the solution was acidified and distilled with a current of steam. A few oily globules floated on the surface of the liquid. These were extracted with ether and the ether evaporated. A small amount of oily residue remained, which was distinctly acid. The oily residue was exactly neutralized with sodium hydrate and precipitated with silver nitrate solution in three fractions:

Fraction 1. 0.0377 gram silver salt gave 0.0162 gram silver = 42.9 per cent silver.

Fraction 2. 0.0206 gram silver salt gave 0.0091 gram silver = 44.1 per cent silver.

Fraction 3. 0.0663 gram silver salt gave 0.3000 gram silver = 45.2 per cent silver.

The three fractions appear to be a mixture of caprylic and œnanthylic acids. Silver caprylate requires 42.9 per cent silver; silver œnanthylate requires 45.5 per cent silver.

A small amount of the insoluble free acids was therefore caprylic acid (octoic acid), the major portion being œnanthylic acid (heptoic acid).

The distillate from which the oily acids were extracted by ether was still slightly acid and was accordingly neutralized with sodium carbonate and precipitated with silver nitrate, two fractions being obtained. The first corresponded to silver carbonate, due to a slight excess of sodium carbonate; the second, only trifling in quantity, indicated the presence of only a trace of formic acid in the free condition.

Œnanthylic, or heptoic, acid seems to be the predominating free acid in the oil, with slight traces of formic and caprylic, or octoic, acids.

COMBINED ACIDS.

The esters in the oil, being combinations of alcohols and acids, serve as a basis for the identification of the acids in combination. In order to accomplish a separation of the combined acids a small quantity of the oil was saponified with alcoholic potassium hydroxid by heating on a water bath for half an hour. After dilution of the mixture with water and separation of the oil the alkaline liquid, which contained a small amount of the oil held in suspension, was shaken out with ether. The liquid was then acidified with sulphuric acid and distilled with steam. The oily globules which separated on the distillate were extracted with ether and the solvent evaporated. A small amount of an oily liquid with very offensive odor remained. This mixture of oily acids was neutralized with sodium hydrate and precipitated with a dilute solution of silver nitrate. Two fractions resulted:

Fraction 1. 0.0430 gram silver salt gave 0.0160 gram silver = 37.2 per cent silver.

Fraction 2. 0.0440 gram silver salt gave 0.0197 gram silver = 44.7 per cent silver.

From the results obtained it is evident that the fractions consist of the silver salt of undecylic acid, which requires theoretically 36.8 per cent of silver, and silver salt of heptoic (œnanthylic) acid, which requires 45.5 per cent of silver.

The aqueous distillate from the above, after being made neutral with sodium carbonate, was evaporated to small volume and precipitated in three fractions with silver nitrate:

Fraction 1. 0.243 gram silver salt gave 0.1837 gram silver = 75 per cent silver.

Fraction 2. 0.3255 gram silver salt gave 0.2370 gram silver = 72.9 per cent silver.

Fraction 3. 0.3492 gram silver salt gave 0.1840 gram silver = 52.9 per cent silver.

The greater portion of the soluble combined acids consisted of valerianic acid, the silver salt requiring 51.6 per cent of silver. A trace of formic acid was also indicated in combination as an ester in fraction 2, above.

The chief acids in combination as esters in the oil appear to be œnanthylic (heptoic) and valerianic, the former being preponderant. Formic and undecylic acids occur only as traces. All of the above are no doubt combined in the oil as esters of borneol.

FRACTIONATION OF THE VOLATILE OIL.

One hundred grams of the original oil were subjected to fractionation and separated into six fractions of 5 degrees each, beginning with 175° C. Those fractions together with the residue were again fractionated in order to insure a better separation of the constituents.

+Table IV.+--Fractionation of oil of wild sage, showing the physical and chemical properties of the fractions.

---------+------------+-----------+--------+----------+-------+--------------- | | |Specific| Rotation | Ester | Fraction.|Temperature.|Distilled. |gravity |in 50 mm. |number.| Remarks. | | | at | tube. | | | | | 24° C. | | | ---------+------------+-----------+--------+----------+-------+--------------- |Degrees C.|Per cent.| |Degrees.| | 1 |Below | 13.6 | 0.9084 | - 9.5 | 2.6 |Eucalyptuslike | 175 | | | | | (cineol) odor. 2 |175 to 180 | 14.0 | .9196 | - 8.1 | 6.7 | Do. 3 |180 to 185 | 6.0 | .9269 | - 7.6 | 8.9 | Do. 4 |185 to 190 | 4.5 | .9313 | - 6.4 | 12.0 |Slightly | | | | | | camphoraceous | | | | | | odor. 5 |190 to 195 | 10.0 | .9401 | - 8.6 | 25.8 |Camphoraceous | | | | | | odor. 6 |195 to 205 | 9.5 | .9478 | - 9.7 | 34.8 |Decidedly | | | | | | camphoraceous; | | | | | | free borneol | | | | | | crystallized | | | | | | in condenser. 7 |205 to 215 | 9.0 | .9562 | -10.6 | 56.4 |Fraction almost | | | | | | solid | | | | | | (borneol). 8 |215 to 230 | 9.5 | .9600 | -10.8 | 75.2 |Fraction | | | | | | partially | | | | | | solidified. 9 |230 to 245 | 3.5 | .9570 | - 5.8 | 70.7 |Few crystals | | | | | | separated. 10 |245 and | 9.0 | .9830 |..........| 47.0 |Dark, sirupy, | above | | | | | camphoraceous. ---------+------------+-----------+--------+----------+-------+---------------

IDENTIFICATION AND SEPARATION OF THE CONSTITUENTS.

Cineol.--Fraction 1, 175° C., possessed a strong eucalyptuslike odor and was tested for cineol by means of iodol. The tetraiodopyrol (iodol) addition product of cineol formed into well-defined, nearly colorless crystals, melting at 110° to 113° C. This crystalline addition product of iodol formed in the first four fractions; in fraction 5, however, only a trace of crystals appeared.

The presence of cineol having been proved, a quantitative estimation of the compound was made in fractions 1, 2, 3, and 4. Fraction 5, which contained only a very small quantity of cineol, did not admit of estimation by the phosphoric-acid method, which is reliable only when large percentages of cineol are present.