J8-Pinene

Further papers in this section include the hydrosilylation of a-pinene and of j8-pinene, ° thiocyanation and selenocyanation of a-pinene, ° cationic polymerization of a- and /3-pinene epoxides,bromination of ( )-c/s-pinonic acid with dioxan dibromide, and straightforward myrtenol (224 R=CH20H) ° and tetrahydroperillyl alcohol syntheses from -pinene epoxide. 

The components of a commercial process employing chromatographic separation are represented on the flowsketch of Figure 15.28. The process is intermittent with very short cycles. The cost breakdown of a plant for the separation of a- and j8-pinenes is given in Table 15.7, which is based on pilot plant work in a 4 in. dia column. That company is no longer in that business thus the test... 

The initial step of the OH-pinenes reaction has been investigated using density functional theory and ab initio methods by Fan et al. [147] (for a- and j8-pinenes) and Ramirez-Ramirez et al. [148] (for y3-pinene). Both studies considered site-specific and stereo-specific (anti and syn position relative to the -C(CH3)2-bridge) addition of OH to the pinene C=C bond, forming four adducts for each pinene. 

Kennedy, J. P. and Chou, T. Poly(isobutyleneSulfur Vulcan-izable, Ozone Resistant Elastomer by Cationic Isomerization Copolymerization. Vol. 21, pp. 1-39. 

A number of papers this year are full reports of earlier communications they include Fallis s synthesis of - and j8-pinene (Vol. 5, p. 37), Bessiere-Chretien s pyridine hydrochloride cleavage of the ether (219) (Vol. 3, p. 16) and the rearrangement of 2-chloro-3-nitrosopinane in benzene solution, catalysed by silica, to give 6-eni/o-chlorocamphor oxime,in contrast to the corresponding 6-exo-cyanocamphor oxime produced by treatment with potassium cyanide.A related paper examines base treatment of the red-brown oily by-product from 2-chloro-3-nitrosopinane formation which yields a -fenchen-6-one oxime (220). " ... 

Pinocarveol has been prepared by the autoxidation of a-pinene, by the oxidation of j8-pinene with lead tetraacetate, and by isomerization of a-pinene oxide with diisobutylalumi-num, lithium aluminum hydride, activated alumina, potassium fert-butoxide in dimethylsulfoxide, and lithium diethylamide. The present method is preferred for the preparation of pinoearveol, since the others give mixtures of products. It also illustrates a general method for converting 1-methylcy-cloalkene oxides into the corresponding exocyclic methylene alcohols. The reaction is easy to perform, and the yields are generally high. 

Eliminations. Allylic esters undergo reductive elimination. Myrtenyl formate gives 82% yield of a mixture of a-pinene and j8-pinene in a ratio of 2 98. However, propargylic formate is defunctionalized without isomerization. ... 

Newspaper, Newspaper journal Toluene, o-,m-,p-xylene, a-/j8-pinene, limonene, aliphatic hydrocarbons (C10-C20) 2... 

Chamblee et al. have reported the reaction of /3-pinene with water at 200 and 250 C. The distribution of products obtained was identical to those obtained under aqueous acid-catalyzed conditions (Fig. 9.30). As a consequence, it is assumed that the reaction in hot water proceeded via carbonium ion intermediates. The reaction with j8-pinene in water at 200°C is relatively fast with 90% conversion in 20 min. However, the yield of terpineol is small (10%) vs the formation of hydrocarbons, which are the major products formed under these conditions. Reactions run at 250°C show even greater hydrocarbon formation. 

Sulfate turpentine is obtained as a by-product during the kraft pulping of pine woods. Vapors periodically released from the top of the digesters are condensed, and the oily turpentine layer is separated and purified by fractional distillation and treatment with chemicals to remove traces of sulfur compounds. Sulfate turpentine is very similar to gum turpentine obtained from the oleoresin of the tree and contains 60 to 70 percent a-pinene, 20 to 25 percent j8-pinene, and 6 to 12 percent other pinenes. Sulfate turpentine from western North America woods contains appreciable amounts of A -carene, which is used as a solvent. In the United States, about 80 percent of the annual production of turpentine is from the kraft pulping of southern pines (approximately 125 million liters). 

According to the SARs of Kwok and Atkinson (1995), over 80% of the OH addition occurs in the position shown, and the oxy radical reacts rapidly and exclusively by dissociation, so that, under high NOj conditions, nopinone is the major product of reaction of OH with -pinene. For example, in a MCMvS.l simulation of a chamber experiment on the OH-initiated oxidation of j8-pinene, Pinho et al. (2007) simulated a 70% yield of nopinone. Experimental determinations of the yield of nopinone in chamber studies using OH initiation have been reviewed by Atkinson and Aschmann (1993) the observed yields are in the range 25-80%, but with a preponderance of measured yields around 25-30%. 

The ozonolysis of the monoterpenes, biogenic species of molecular formula CioHm (e.g., a- and /3-pinene), provides a significant source of secondary organic aerosol. A number of multi-functional organic acids, such as norpinic acid from j8-pinene ozonolysis, and pinonic acid and pinic acid from a-pinene ozonolysis, have been conclusively identified as components of the organic aerosol formed (e.g., Presto et al., 2005 and references therein). As summarized in table VI-F-1, these acidic species possess very low vapor pressures (typically < 10 " Pa at 298 K, Bilde and Pandis, 2001), and thus have a strong tendency to partition to the condensed phase, where they are removed via depositional processes. The low vapor pressures preclude any studies of their gas-phase kinetics. However, the structure-activity relations (SARs) of Kwok and Atkinson (1995) can be used to estimate rate coefficients of about (1-5) xl0 cm ... 

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