Hydration of alpha-pinene under various conditions was studied and compared with the literature. Optimal reaction conditions have been established for the hydration of alpha-pinene and crude turpentine oil in the absence of catalyst and using a low volume of acetone. A detailed reaction product analysis is reported. The main hydration product, alpha-terpineol, was obtained at a yield of 67 wt % of the initial alpha-pinene by reacting with 15% aqueous sulfuric acid and an excess of acetone in an oil bath heated to 80-85 degrees C over the course of 4 h. A progressive transformation of alpha-terpineol to 4-(2-hydroxypropyl)-1-methylcyclohexanol (1,8-terpine) takes place as the hydration time exceeds 4 h. A crude turpentine oil sample was also hydrated under conditions similar to those of alpha-pinene. The alpha-terpineol yield was 77 wt % of the initial alpha-pinene in the crude turpentine oil. The chemical analysis of the crude turpentine oil before and after hydration was carried out, and the distribution of the products was discussed.
"Aguirre et al. (2005) used hydrochloride acid, acetate acid, chloro acetic acid and oxalic acid as catalyst for the hydration of -pinene. Choro acetic acid was found as good catalyst for the production of terpineol from pinene.The highest selectivity was 95.5% with the conversion of 10%, whereas the higher conversion was 99% with selectivity of 69%, after 4 h of reaction at 70 o C . Pakdel et al. (2001) used sulphate acid as catalyst to synthesize terpineol from turpentine, in the presence of excess acetone as solubility promoter. They reported 67% of selectivity to terpineol although the conversion was not reported . "
[Show abstract][Hide abstract] ABSTRACT: Turpentine is natural essential oil obtained by distillation of the raw oleoresin collected from pine trees, in which α-pinene is the main component of most turpentine oils. Turpentine from Indonesia contains 65-85% α-pinene , 1% camphene, 1-3% β-pinene, 10-18% 3-carene and limonene 1-3%. When treated with water in the presence of acid catalyst, α-pinene is hydrated to α-terpineol which can be used as perfume, repellent of insect, antifungal and disinfectant. This work presents the result of α-terpineol synthesis by hydration of turpentine. The study investigates that the effect of catalyst (sulfuric acid, chloro acetic acid), temperature (60, 70, 80, 90oC), the mol ratio of chloro acetic acid to α-pinene (0.8/1; 1.6/1; 2.4/1; 3.2/1; 4/1), and stirring rate (264, 546, 954 rpm). It suggested that the best condition for the hydration of turpentine was achieved at temperature of 80oC, reaction time of 240 min, mol ratio of chloro acetic acid catalyst to α-pinene of 2.4/1 and the stirring rate of 546 rpm. The conversion of hydration of turpentine to α-terpineol was obtained to be 54.13%.
Keyword: Turpentine, α-Pinene, Hydration, α-Terpineol
17th ASEAN Regional Symposium on Chemical Engineering, Bangkok,Thailand; 11/2010
[Show abstract][Hide abstract] ABSTRACT: While the contribution of 1,8-cineole to the aroma of wine has been reported, it is a matter of controversy that the vineyards producing such wines are surrounded by Eucalyptus trees, which may contribute their essence to the grapes. However, experimental information presented in this paper suggests that 1,8-cineole can be produced by chemical transformation of limonene and alpha-terpineol, and this process may be responsible for the occurrence of Eucalyptus-like aroma in Tannat wines from vines not grown in the vicinity of Eucalyptus trees. A mechanism for the chemical transformation of these aroma compounds is proposed.
Journal of Agricultural and Food Chemistry 04/2005; 53(5):1633-6. DOI:10.1021/jf040332d · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Monoterpenes in exudates, phloem, and sapwood have received considerable attention relative to the active defenses of pine trees. However, little is known about the composition and function of the heartwood monoterpenes. To address this deficiency, monoterpene contents and relative compositions were determined for sapwood and heartwood samples from longleaf pine (Pinus palustris Mill.) stumps monitored in the field for a 1 year period postharvest. Gas chromatography - mass spectrometry analysis of sapwood and heartwood sample extracts showed the total monoterpene contents for both declined at essentially the same rate. For sapwood, α-pinene continued to comprise about 75% of all compounds detected, while the proportion of β-pinene declined with time (15%-7%). For the heartwood, lower proportions of both α- and β-pinenes (64% and 10%, respectively) were offset by higher proportions of other monoterpenes (e.g., limonene, α-terpineol, borneol). The low proportion of β-pinene in very old turpentine and lightwood stump samples further suggested the lower stability of this particular monoterpene. While it has not been specifically demonstrated that the monoterpenes have an active role in the decay resistance of longleaf pine stump heartwood, these compounds do persist for a very long time and thus are available should they serve this function.
Canadian Journal of Forest Research 07/2009; 39(7). DOI:10.1139/X09-063 · 1.68 Impact Factor
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