P-phellandrene

Foliage of Douglas fir had only trace amounts of (+)-camphene in trees from the coast but major concentrations in trees from the other three sites, hi contrast, ter-pene mixtures from lodgepole pine leaf and bole tissues had nearly the same levels of the major compound, (-)-P-phellandrene, and minor components regardless of origin. Patterns of variation in the other species were less extreme. 

Rycroft et al. (1999) identihed the major components of plants from six locations in western Scotland and four from the Azores using nuclear magnetic resonance (NMR) fingerprinting and GC-MS. The terpene P-phellandrene [129], which may be responsible for the aroma of material crushed in the held, was detected in all specimens. The major components, which appear in Fig. 5.6, were shown to be methyl eveminate [444], the four methyl orcellinate derivatives [445 8], the two 9,10-dihydrophenanthrene derivatives [449] and [450], the newly described phthalide killamiensolide [451], and the bibenzyl [453]. Methyl eveminate was the major compound in all 10 specimens other compounds were more varied in their occurrence. Killamiensolide was not isolated as such but was detected when extracts were acetylated yielding, among other compounds, [452]. The presence of the bibenzyl compound [453] in more than trace amounts in P. killarniensis raises the possibility that it represents contamination from P. spinulosa with which it was growing at the one site. 

P-parinaric acid, physical properties, 5 33t P-pentenoic acid, physical properties, 5 3 It P-peroxylactones, 18 484 Beta phase titanium, 24 838 in alloys, 24 854-856 properties of, 24 840, 941 P-phellandrene, 24 493 P-picoline, 21 110 from acrolein, 1 276 uses for, 21 120 P-pinene, 3 230 24 496-497 major products from, 24 478 /-menthol from, 24 522 as natural precursor for aroma chemicals, 3 232 terpenoids from, 24 478-479 P-propiolactone, polymerization of, 14 259 P-quartz solid solution, 12 637—638 Beta ratio, in filtration, 11 329—330 Beta (P) rays, 21 285 P-scission reactions, 14 280-281 P-skytanthine, 2 101 P-spodumene solid solution, 12 638-639 P-sulfur trioxide, 23 756 P-sultones, 23 527 P-tocopherol, 25 793 P-tocotrienol, 25 793 P-vinylacrylic acid, physical properties, 5 33t... 

Concerning steric factors, 43 is attacked in the most hindered position ( inverse effect of substitution ) likewise, 39 is attacked at the most hindered carbon. Obviously, the transition states for the formation of 44 or 50 show limited sensitivity to the degree of substitution, and the relief of ring strain is a more significant factor than the steric hindrance in the transition state. On the other hand, steric factors are important in systems such as P-phellandrene radical cation 40 which is attacked at the xo-methylene carbon (most easily accessible), or the tricyclane radical cation 56 which is attacked at the less hindered 3° carbon further removed from the dimethyl-substituted bridge (approach a). Both reactions also benefit Irom the formation of the most highly substituted, hyperconjugatively stabilized free radicals. 

The odor of wood is mostly caused by the terpenes contained in the resin. Differences in the composition of several kinds of resin have been investigated (Moyler and Clery, 1997). There is also some data available on the emissions of treated wood, wood products and furniture (Baumann, Batterman and Zhang, 1999 Risholm-Sundmann et al., 1998 Salthammer, 1999a Salthammer, Schwarz and Fuhrmann, 1999). Besides terpenes like a-pinene, P-pinene, A3-carene, longi-folene, P-phellandrene, camphene, myrcene, carvone, limonene, caryophyllene,... 

Electrooxidation of (—)-a/p/ -phellandrene in aTHF/H20(15/l)—H2S04/NaC104-(graphite) system can lead to (-t-)-trans-yabunikkeol, l(7),2-p-menthadiene-6-ol, in 40% yield 63b). 

Terpenes are the main constituents of the volatile essential oil of M. koenigii leaves, which are used for curry flavouring (MacLeod and Pieris, 1982). The oil of M. koenigii produces less than 4% of other components, with eight monoterpene hydrocarbons (about 16%) and 17 sesquiterpene hydrocarbons (about 80%). The major constituents responsible for aroma are P-caryophyllene, P-gurjunene, P-elemene, P-phellandrene and P-thujene (Kumar et al., 1999). The volatile oils from the leaves of six species of the genus Murraya have been studied by GC-MS and about 60 monoterpene and sesquiterpenes components were identified. From these results, and published... 

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