This alcohol, the constitution of which has not yet been definitely determined, was recently found in the laboratory of Schimmel & Co.,2) to occur free and as ester, also in both optical modifications in gingergrass oil.
This alcohol is a colorless, rather viscid oil of a peculiar odor reminding of linalool and terpineol. From geraniol, its companion in gihgergrass oil, it can be separated only with difficulty. Its isolation can best be effected by heating the mixture of alcohols with 2 parts of 90 p. c. formic acid on a waterbath to a temperature of 80 °,3) whereby only the geraniol is destroyed. For two preparations thus purified, Walbaum and Hiithig4) record the following constants:
B. p. 226 to 227° (767 mm.), 92 to 93,5° (5 mm.); d15o0,9510; aD - 13° 18'; nD20o1,49629.
B. p. 228 to 229° (755 mm.), 94 to 96° (4 to 5 mm.); d15o0,9536; aD + 12°5'; nD20o1,49761.
When oxidized with Beckmann's chromic acid mixture, di-hydrocuminic aldehyde, C10H14O, results, thus proving that the alcohol in question, C10H16O, is a dihydrocuminic alcohol. Since no crystalline derivative of the alcohol has yet been obtained, it is identified by its oxidation to the aldehyde, the semi-carbazone of which melts at 198 to 198,5°.
1) Report of Schimmel & Co. April 1910, 173.
2) Report of Schimmel & Co. April 1904, 57; October 1904, 44; Walbaum and Huthig, Journ. f. prakt. Chem. II. 71 (1905), 464.
3) Stronger formic acid and higher temperatures are to be avoided since the alcohol is thereby dehydrated to cymene. Even when the precautions stated are taken this change will take place to a slight extent.
4) Loc. cit 466.