Terpin

Dehydration. Dehydration of hydroxy fatty acids is quite common. Other compounds undergo the same reaction, eg, elymoclavine [548-43-6] to agroclavine [548-42-5] chanoclavine [2390-99-0] and other compounds and <7j -terpin hydrate [2541-01-63] to a-terpineol [98-55-5] (19). 

Synthetic pine oil is produced by the acid-catalyzed hydration of a-pinene (Fig. 1). Mineral acids, usually phosphoric acid, are used in concentrations of 20—40 wt % and at temperatures varying from 30—100°C. Depending on the conditions used, alcohols, chiefly a-terpineol (9), are produced along with /)-menthadienes and cineoles, mainly limonene, terpinolene, and 1,4- and 1,8-cineole (46—48). Various grades of pine oil can be produced by fractionation of the cmde products. Formation of terpin hydrate (10) from a-terpineol gives P-terpineol (11) and y-terpineol (12) as a consequence of the reversible... 

Pine oils can be fractionally distilled to produce a higher a-terpineol product, but usually contain bomeol and y-terpineol, along with small amounts of other components. High grade perfumery a-terpineol can be made by the partial dehydration ofyvmenthane-l,8-diol (terpin hydrate) under mildly acidic conditions (117,118). 

Terpin hydrate [2451-01-6] (10), one of the most weU-known expectorants, is isolated from cmde pine rosin left after the distillation of volatile terpene hydrocarbons and alcohols. It is also manufactured from turpentine (a-pinene) by acid-cataly2ed hydration. Terpin hydrate may exist as cis and trans isomers, but only the cis isomer forms a stable, crystalline monohydrate. Terpin hydrate is available in the United States only in prescription products. 

Common plasticizers are used to reduce viscosity and to aid adhesion. Most plasticizers commonly utilized in PVC are also used in urethanes. One of the most common plasticizers is diisodecyl phthalate, though many others are used equally effectively. In some cases tackifiers, such as certain esters or terpine phenolics, are utilized to obtain specific adhesion characteristics. 

The artificially obtained terpin, prepared as described below, has the follow ing characters —... 

Apparently only a-terpinene and -y-terpinene have been found occurring naturally in essential oils. All the terpinenes are formed artificially from other terpinenes, or from geraniol, cineol, terpin hydrate, linalol, dihydro-carveol, and numerous other compounds. 

Terpine hydrate, CioHig(OH)3 + HjO, is a crystalline alcohol resulting from the action of dilute mineral acids on either pinene or limonene. It can be prepared by several different methods, of W hich the following is typical A mixture of 8 parts of oil or turpentine, 2 parts of alcohol, and 2 parts of nitric acid of specific gravity 1 255 IS allowed to stand for several days in a flat basin. After standing for a few days the mother liquor is poured off from the crystals of terpine hydrate, and neutralised with an alkali, after which a second crop of crystals is obtained. 

Strategy ur-Terpined, a monoterpenoid, must be derived biologically from geranyl diphos-... 

M Frezza, C Di Padova, G Pozzato, M Terpin, E Baraona, CS Lieber. High blood alcohol levels in women the rold of decreased gastric alcohol dehydrogenase and first-pass metabolism. N Engl J Med 322 95-99, 1990. 

Heim A, Terpin A, Steglich W (1997) Angew Chem Int Ed Engl 36 155... 

Terpenoid pheromones, 24 473 Terpenoid skeletons, 24 469 biosynthesis of, 24 471 Terpin hydrate, 3 231 a-Terpineol, 24 477, 509-512, 3 231 hydrogenation of, 24 512 a-Terpinyl acetate, 24 512 a-Terpinyl chlorides, 24 479 a-Terpinyl esters, 3 231 y-Terpinene, 3 230 Terpinolene, 24 493 Terpolymers... 

DIPA See diisopropanolamine. dip-o or de T pe a dipentene org chem A racemate of limonene. dT pen,ten dipentene glycol See terpin hydrate. dT pen.ten glT,k6l dipentene hydrochloride See terpene hydrochloride. dT pen,ten,hT-dr3 kl6r,Td ) diphacinone orgchem C23H16O3 A yellow powder with a melting point of 145-147°C used to control rats, mice, and other rodents acts as an anticoagulant. do fas-3,non ... 

---