Santalene employed Recovered hydrocarbon d20o 0,9034; aD - 9° 13' d90o 0,8973; aD - 1°15'.

11. Santalol, C15H240. To the extent of over 90 p.c, oil of sandal wood consists of santalol, which is not only quantitively but also medicinally its most important constituent, since the therapeutic action of the oil depends upon it. Santalol is not a chemical unit, as one might have inferred from the investigations of P. Chapoteaut1). As first pointed out by Schimmel & Co.2), it can be resolved into two isomers by fractional distillation, namely into a- and B-santalol. Moreover, the formula assigned to santalol by Chapoteaut and later by Guerbet3), viz., C15H260 is not correct4). Acetylation and analyses5) of the alcohols purified through the phthalic acid derivatives, as described below, revealed the formula C15H240.

For the properties and derivatives of the santalols see vol. I, p. 400. These data should be supplemented by the constants since determined by Schimmel & Co.6) for the santalols regenerated from the acid phthalates and carefully fractionated.

a-SantaloI: b. p. 148° (4,5 mm.); d16o0,9788; aD + l°13'; nD20o 1,49915, mol.-refr. found 66,23, computed for C15H24O/1 65,93.

B-Santalol: b.p. 158 to 158,5° (5 mm.); d15o0,9728; aD - 41°47'; nD20o 1,50910, mol.-refr. found 67,77, computed for C15H240/2 67,64.

On the strength of his extensive researches, Semmler7) assigns to the a-santalol the accompanying constitutional formula which also explains its relation to a-santalene.

1) Bull. Soc. chim. II. 37 (1882), 303; Chem. Zentralbl. 1882, 396.

2) Report of Schimmel & Co. April 1899, 38.

3) Compt. rend. 130 (1900), 417 and 1324. - Bull. Soc. chim. 23(1900), 540 and 542.

4) Report of Schimmel & Co. April 1900, 42.

5) von Soden, Arch, der Pharm. 238 (1900), 353. •) Report of Schimmel & Co. October 1910, 127.

7) Berl. Berichte 40 (1907), 1120, 1124; 41 (1908), 1488; 42 (1909), 584; 43 (1910), 1893.

Ch2 CH a-Santalol and a-Santalene.

219 Oil Of Sandal Wood 50

In order to obtain pure santalol, the following process is used1): 100 g. of East Indian sandal wood oil are heated with an equal weight of phthalic acid anhydride and benzene for an hour on a water bath to 80°. The acid phthalate thus formed is combined with alkali by shaking the mixture with soda solution and dissolved in much water. In order to remove the nonalcoholic constituents, the aqueous solution is shaken out three times with ether. The acid esters are removed from the aqueous solution by the addition of more than the computed amount of diluted sulphuric acid. They are then separated and saponified with alcoholic potassium hydroxide. The liberated santalol is freed from excessive alkali and alcohol by washing with water.

12. Santa/a/, C15H22O. According to Chapoteaut and Guer-bet-) the aldehyde corresponding to santalol likewise occurs in sandal wood oil. It has an odor strongly reminding one of pepper and, according to Guerbet, boils at 180° (40 mm.). Its semicar-bazone, which crystallizes in small needles, melts at 212°.

Inasmuch as more recent investigations have not verified the occurrence of an aldehyde of the above mentioned properties, the statements made by Guerbet should be taken with caution.

1) Report of Schimmel & Co. April 1899, 38. 2) Loc. cit.

It is possible that the semicarbazone obtained by Guerbet was an impure derivative of nortricyclocksantalal of which the pure compound melts at 223 to 224°.

A. C. Chapman and H. E. Burgess1) designate as santalal fraction 301 to 306° of sandal wood oil, which they have oxidized with potassium permanganate to santalenic acid C13H20O22). In a second contribution Chapman3) designates this fraction santalol without further comment. Probably he had his doubts as to the aldehyde nature of the substance in question. As santalal Semmler and Bode-) designate the aldehyde C15H220 corresponding to santalol and which they obtain by oxidizing the alcohol with chromic acid in acetic acid solution. Regenerated from its semicarbazone (m. p. abt. 230°), it has the following properties: b.p. 152 to 155° (10 mm.); d20o 0,995; aD + 13 to +14°; nD 1,51066; mol. refr. found 65,6, computed for C15H22 0/64,63.

13. Teresantalic acid, C10H14O2. The acid constituents of sandal wood are contained therein partly in the free state, partly as ester. According to F. Muller4), teresantalic acid, which crystallizes in well formed prisms, boils at about 150° (11 mm.), melts at 157° and shows [a]D - 70° 24' in a 25 p.c. alcoholic solution6). It occurs principally in the free state (about 0,5 p.c.) in the oil and can be removed by shaking the oil with dilute sodium hydroxide solution. According to the investigations of F. W. Semmler and K. Bartelt5) teresantalic acid is tricyclic.

14. Santalic acid, C15H2202 is the second acid which, according to Guerbet0) occurs in sandal wood oil. It is described as a viscid colorless liquid with slightly acid properties, boiling at 210 to 212° (20 mm.).

Upon saponification of the nitrile obtained from a-santalal, Semmler and Bode7) obtained an acid C15H2202 which they call l) Proceed, chem. Soc. No. 168 (1896), 140.

-) Before oxidation with permanganate Semmler and Bode (Berl. Be-richte 40 [1907], 1124, comp. also ibidem 43 [1910], 1722) obtained dihydroxy-dihydrosantalol, C15H26O3 and tricycloeksantalic acid C12H1602 (m.p. 71 to 72°).

5) Journ. chem. Soc. 79 (1901, 134.

4) Arch, der Pharm. 238 (1900), 374.

5) Berl. Berichte 40 (1907), 3101.

6) Loc. cit.

7) Berl. Berichte 40 (1907), 1129.

santalic acid and which boils at 192 to 195° (9 mm). It has not been ascertained whether it is identical with the one described above.

According to F. Muller the saponification liquids of sandal wood oil contain another or even several other acids which have not yet been investigated.