JS-Pinene

No reactions have been observed when methylenecyclopentane (182), methylenecyclohexane (183), or A1(7)-p-menthene (184) were submitted to photosensitized oxygenation.187 On the other hand, methylene-cycloheptane (185)1B7, jS-pinene (187)197, A4<10)-carene (190),202 and sabinene (193)205 undergo slow photosensitized oxygenation reactions giving rise to the formation of primary alcohols 186,189,191,192, and 194, respectively, after reduction of the primarily formed... 

Tarragon Artemisia dracunculus L. French tarragon or Italian tarragon oU jS-pinene and sabinene (24-47) Russian tarragon or German tarragon sabinene(ll-47), methyl eugenol (6-36), elemicin (1-60)... 

Approximately 230 volatile compounds have been identified in raspberry fruit [35]. The aroma of raspberries is composed of a mixture of ketones and aldehydes (27%) and terpenoids (30%), alcohols (23%), esters (13%) and furanones (5%). The raspberry ketone (Fig. 7.5) along with a-ionone and jS-ionone have been found to be the primary character-impact compounds in raspberries. Other compounds such as benzyl alcohol, (Z)-3-hexen-l-ol, acetic acid, linalool, geraniol, a-pinene, jS-pinene, a-phellandrene, jS-phellandrene and jS-caryophyllene contribute to the overall aroma of mature red raspberries [101-105]. The most important character-impact compounds of raspberries are summarised in Table 7.3. 

Ozonolysis of pinenes contributes to OH radical and SOA formation. The latter has been speculated to be responsible for the formation of "blue haze". Hence, it is of vital importance to quantitatively understand the roles of ozonolysis of a- and jS-pinenes on both OH and SOA formation in the troposphere. The O3 reaction with both pinenes follows the Criegee mechanism, similar to that of iso-prene. The initial step proceeds through cycloaddition of O3 to the C=C double bond of each pinene, forming a primary ozonide (POZ). The available reaction energy is retained as the internal energy of the product, resulting in formation... 

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 jS-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... 

Spectrum of the copolymer to fully crowded gem-dimethyl sequences, i.e., isobutylene-isobutylene or ii for brevity, sequences. Poly(jS-pinene), a molecule that contains uncrowded gem-dimethyl groups, shows a resonance band at 0.85. On the basis of this, we assigned the band appearing at 0.8 5 in the spectrum of the copolymer to uncrowded gem-dimethyls indicating a P-pinene unit that is followed by another j3-pinene unit i.e, flS sequences. The central band at 1.05 of the three partially unresolved bands in the spectrum of the copolymer is a new gem-dimethyl band... 

The sequence distribution of isobutylene and jS-pinene units in the copolymers was elucidated by an analysis of the gem-dimethyl chemical shifts. -Run numbers have been calculated and found to coincide with theoretical values for statistical copolymers (Fig. 5). 

The known tricyclic ether (370) derived from (- )-jS -pinene (369) has been used as an intermediate in a new synthetic route (Scheme 36) to (+ )-hinesol (379) and 10-... 

Turpentine isolated from the Krafft process is referred to as sulfate turpentine, and that obtained by tapping living trees is known as gum turpentine. Turpentine is the monoterpene fraction of pine oil and contains mostly a- and jS-pinene, present in a ratio of about 7 3 (a jS), the exact ratio depending on the species of tree involved. Pure a- and f-... 

The two main disadvantages of this route are the cost of jS-pinene and the presence of trace amounts of chlorinated materials, which must be removed from the product. 

Professor Wolinsky s work was intended to clean up the stereochemical complications of earlier investigations that use optically impure a-pinene, which, on top of everything else, also contained jS-pinene in some cases without the researchers knowing it. See C. Wagner and A. Ginzberg, Ckem. Ber., 29, 886 (1896) G. G. Henderson and J. K Marsh, J. Chem. Soc., 119, 1492 (1921). 

Interesting examples of optical resolutions include the use of dicarbonyl-rhodium(i) 3-trifluoroacetyl-(li )-camphorate for g.l.c. separation of chiral olefins and of dimeric nickel(ll) bis-(3-trifluoroacetyl-li -camphorate) for an improved separation of chiral epoxides (cf. Vol. 8, p. 8). The resolution of (i /5)-pantoic acid with chiral amines derived from a- and jS-pinene (Vol. 7, p. 43, ref. 420) may signal their more widespread use. 1,3-Dithian 1-oxide has been resolved. ... 

The structure of the major FeCla-catalysed ene adduct of chloral to (15,55)-(-)-/3-pinene (Vol. 8, p. 54) is (209). Preferred ene reaction of PhS02NS0 with 8-pinene has been used for the almost quantitative separation of a- and /8-pinene another application of this reaction allows the conversion of a-pinene into jS-pinene via a triple allylic transposition sequence of ene-reaction, reduction, reductive silylation, and hydrolysis/ Ene reactions of jS-pinene under pressure have been observed (74—100% yields) at room temperature thus limiting, for example, retro-ene side-reactions. The full papers on a-pinene/allo-ocimene pyrolysis (c/. Vol. 7, p. 12) and on the thermal rearrangement of (208 X = H or Me) have been published (Vol. 4, pp. 61, 62) (208 X = H) is reported to yield only (210) in contrast to unpublished observations of Prater who has reported the rearrangement of (210) to (208 X = H) and the formation of p-menthadiene derivatives from (208 X = H or 0-)6 ... 

The formation of crystalline Ag+ complexes may provide a simple way of purifying particular alkenes, or for separation of mixtures, e.g., of 1,3-, 1,4- and 1,5-cyclooctadiene, or of the optical isomers of a- and jS-pinene, because of the differing stabilities of the complexes. 

Planar chiral compounds should also be accessible from the chiral pool. An example (with limited stereoselectivity) of such an approach is the formation of a ferrocene derivative from a jS-pinene-derived cyclopentadiene (see Sect. 4.3.1.3 [81]). A C2-symmetric binuclear compound (although not strictly from the chiral pool, but obtained by resolution) has also been mentioned [86]. Another possibility should be to use the central chiral tertiary amines derived from menthone or pinene (see Sect. 4.3.1.3 [75, 76]) as starting materials for the lithiation reaction. In these compounds, the methyl group at the chiral carbon of iV,N-dimethyl-l-ferrocenyl-ethylamine is replaced by bulky terpene moieties, e.g., the menthane system (Fig. 4-2 le). It was expected that the increase in steric bulk would also increase the enantioselectivity over the 96 4 ratio, as indicated by the results with the isopropyl substituent [118]. However, the opposite was observed almost all selectivity was lost, and lithiation also occurred in the position 3 and in the other ring [134]. Obviously, there exists a limit in bulkiness, where blocking of the 2-position prevents the chelate stabilization of the lithium by the lone pair of the nitrogen. 

Ring expansion of a- and fi-pinene. When either a- or jS-pinene, (1) or (2), is heated neat with an initial pressure of 30 psi CO at 160° for 68 hr. with an equimolar amount of iron pentacarbonyl, two ketones, (3) and (4), are obtained, formed by insertion of CO into the cyclobutane ring together with some a-pinene. Both ketones are optically active. The Cotton effects are of nearly the same... 

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