Z-a-Pinene

The oil contains Z-a-pinene, Z-phellandrene, sylvestrene, cadinene, and bornyl acetate. Bocker and Hahn have recently isolated from the oil an aldehyde of the formula CjjHjigO, an oxygenated body of the formula CjjHj O, the nature of which has not yet been determined, and a hody of the formula CgHj O, having the characteristic odour of the oil. This body is a cyclic compound, and has been named pumilone, having the general characters of a ketone. It has the following characters —... 

It contains Z-a-pinene, Z-limonene, hornyl acetate, lauric aldehyde, probably traces of decyl aldehyde, and the hydrocarbon santene, CjHj. An oil is also distilled from the young cones of this tree. It contains more terpenes than the leaf oil, and has the following characters —... 

Among the aldehydes isolated from the oil methyl-vanillin was found, which had never previously been found in an essential oil. Citral, Z-a-pinene, and methyl-isoeugenol are also present in the oil. 

Artemisia campestris, var. odoratissima, is also an Algerian plant, yielding the so-called Oil of Gouft. It has been examined by Jeancard and Satie, and by Bertrand-Fils. The oil contains geraniol, geranyl acetate, Z-a-pinene, and probably nopinene. Its characters are as follows —... 

That the oil contains the following constituents, Z-a-pinene, d-a pinene, Z-limonene, Z-borneol, bornyl acetate and other esters of bomeol, Z-camphor, cineol, salicylic acid, aldehydes, formic, acetic, butyric ( ) and isovaleric acids, a non-volatile acid or lactone, and a blue constituent of high boiling-point. 

It contains Z-a-pinene, about 10 per cent, of eucalyptol, pheUandrene, eudesmol, and a sesquiterpene. 

Alloocimene Manufacture. a-Pinene (8) is converted thermally first to cis-ocimene (17), which rearranges to give about 40—50 wt % of the two alloocimene isomers, ie, alloocimene [7216-56-0] (53) and 4-trans-(i-trans-2S[oo[Pg.417]

To a stirred — 78 C solution of 5.85 mL (62.5 mmol) of 3-methoxy-l-prnpene in 25 mL of THf- are added 43.1 mL (50 mmol) of 1.16 M. vcc-butyllithium in cyclohexane over a 20-25 min period. The mixture is stirred at — 78 °C for an additional 10 min, and diisopinocampheyl(methoxy)borane [50 mmol prepared from (+ )-a-pinene] in 50 mL of THF is added. This mixture is stirred for 1 h, then 8.17 mL (66.5 mmol) of boron trifluoride diethyl etherate complex are added dropwise to give a solution of diisopiuocampheyl[(Z)-3-inethoxy-2-propenyl]borane. Immediately. 2.8 mL (50 mmol) of acetaldehyde are added and the mixture is stirred for 3 h at — 78 rC and then allowed to warm to r.t. All volatile components are removed in vacuo, then the residue is dissolved in pentane. The insoluble fraction is washed with additional pentane. The combined pentane extracts are cooled to 0 JC and treated with 3.0 mL (50 mmol) of ethanolamine. The mixture is stirred for 2 h at 0rC and is then seeded with a crystal of the diisopinocampheylborane-ethanolaminc complex. The resulting crystals arc filtered and washed with cold pentane. The filtrate is carefully distilled yield 5.6 g (57%) d.r. (synjanti) >99 1 (2/ ,37 )-isomer 90% ee bp 119-120 C/745 Torr. 

Figure 4. LC separation of a terpene mixture. 1, Thymol 2, p-cymene 3, y-terpinene 4, a-terpinene 5, 3-pinene 6, a-pinene. Column 30 cm x 0.22 mm I.D. 3-ym Spherisorb ODS. Mobile phase methanol-water (80 20) Detection TIC (ions of m/z <40 suppressed).

Prslparativ wegen der hohen optischen Ausbeuten besonders interessant ist die von Brown und Zweifel (51, 53, 54, 325) entdeckte asymmetrische Hydroborierung 1,2-di- oder trisubstituierter Athylen-Doppelbindungen. Man setzt hierbei das aus (+)-a-Pinen, NaBH und BFg leicht zugang-liche (—)-Diisopinocamphenylboran VII mit cis-Olefinen um und oxy-diert die entstehenden Borane unter Retention der Konfiguration zu sec. Alkoholen. Auf diese Weise erhalt man z.B. aus cis-Buten-(2) mit p = 87% (R)(-)-Butanol- 2). 

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. 

More recently, the degradation of a-pinene by Pseudomonas jluorescens NCIMB 11671 was described [97,98]. A novel pathway for the microbial breakdown of a-pinene (119) was proposed, Fig. (23). The attack is initiated by enzymatic oxygenation of the 1,2-double bond to form the epoxide (127). This epoxide then undergoes rapid rearrangement to produce a novel diunsaturated aldehyde, occurring as two isomeric forms. The primary product of the reaction (Z)-2-methyl-5-isopropylhexa-2,5-dien-l-al (trivial name isonovalal) (128) can undergo chemical isomerisation to the -form (novalal) (129). Isonovalal, the native form of... 

Crotyldlisopinocampheylborane. IpC2BCH2CH=CHCH3 (1). The (Z)-isomer is prepared by reaction of (Z)-crotylpotassium with methoxydiisopinocampheylbo-rane [obtained from (- )-a-pinene] to form an ate complex, which is converted into (Z)-l on reaction with BF3 etherate at -78°. The (E)-isomer is prepared similarly from (E)-crotylpotassium. Reaction of acetaldehyde with (Z)-l at - 78° results in (2S,3S)-3-methyl-4-pentene-2-ol (2) in 99% diastereoselectivity and 95% enantioselectivity (equation I). A similar reaction with (E)-l provides (2S,3R)-2. 

Reaction of borane (as a complex with dimethyl sulphide) with optically pure (+)-a-pinene (in 15% excess) results in the almost exclusive formation of di-isopinocampheylborane (Ipc2,BH)67 (Section 4.1.7, p.421). The use of this optically pure borane in the hydroboration of the prochiral (Z)-but-2-ene, followed by oxidation, yields (R)-(—)-butan-2-ol (ee 98.1%) (Expt 5.45). Interestingly, monoisopinocampheylborane (IpcBH2) with (Z)-but-2-ene gives (S)-(+)-butan-2-ol, and hence the importance of careful reagent preparation is emphasised.68... 

GC—O experiments of a waxed and oiled parquet floor revealed acetaldehyde, methyl propanal, 3-methyl butanal, pentanal, hexanal, heptanal, a-pinene, 1-octen-3-one, 3-pinene, octanal, l-nonen-3-one, nonanal, Z-2-nonenal and E-2 nonenalas the most important odorants (Mayer, Breuer and Mayer, 2000). In contrast the less intense odor of varnished parquet floor was mostly caused by acetaldehyde, butanal, 3-methyl butanal, pentanal, hexanal, a-pinene, benzaldehyde, l-octen-3-one, P-pinene and acetophenone. 

An alternative route to Z-(-)-carvone (20) was developed from the more abundant (-)-a-pinene (2), albeit a somewhat lower overall yield (Scheme 5.7).36 The process involves hydroboration of 2 followed by oxidation of the resultant alcohol. Subsequent treatment of the /-isopinocamphone... 

The catalyst precursor complex [ Rh(COD) Diop] BF4 has been used for the screening of five substrates containing prochiral C=C double bond (COD = 1,5-cyclooctadiene) [266]. These were methylacetamidoacrylate (SI), Z-a-methylacetamidocinnamate (S2), dimethylitaconate (S3), methone (S4) and rac-a-pinene (S5) (see Figure 4.56). Activated C=C bonds such as those in the two acetamido derivatives were more reactive. The most reactive molecule is the less sterically hindered substrate methylacetamidoacrylate. Reaction was less pronounced for unsubstituted and sterically hindered substrates such as methone. The reduction of C=0 bond in a-pinene is more difficult. These results are in agreement with the general trends reported for asymmetric hydrogenations. 

Erhitzt man ein Gemisch aus Phosphor(V)-sulfid, Schwefelwasserstoff und Olefin im Au-toklaven auf 70°-140°, so entstehen die erwarteten Triester in hohen Ausbeuten z.B. mit a-Pinen Tetrathiophosphorsaure-tris-(2,6,6-trimethyl-bicyclo[3.Ll hept-3-ylester)594. Tetramethylammonium-Salze von Tetrathiophosphorsaure-diestern werden mit Alkylha-logeniden in guten Ausbeuten alkyliert595-597 ... 

Rate constants and activation energies for liquid- and gas-phase isomerization of a-pinene have been determined.310 The activity of metal sulphate monohydrates in isomerizing a-pinene is correlated with the strength of co-ordination of the water of crystallization to the metal ion.3" Pyrolysis of chrysanthanol acetate (217 R = Ac) gives citronellal and the (E)- and (Z)-3,7-dimethylocta-l, 6-dien-l -ol acetates in 20, 28, and 3% yields respectively formation of the enol acetates is consistent with a biradical or a concerted pathway.312 Further work directed towards C-l—C-7 bond pyrolysis of pinane derivatives shows C-l—C-7 C-l—C-6 bond cleavage ratios of 4 51 for (217 R = Ac), 13 22 for (217 R = H), 6 7 for (218 R = H), and 43 35 for (218 R = Me) the expected acyclic and cyclic alcohol, aldehyde, and ketone pyrolysis products are obtained.313 The ene reaction between /3-pinene and methyl... 

The use of enantiopure allylic boranes in reactions with achiral aldehydes results not only in high diastereoselection, but also in high enantioselectionP Pure (Z)- and )-crotyldiisopinocampheylboranes can be prepared at low temperature from (Z)- or E) crotylpotassium and S-methoxydiisopinocampheylborane, respectively, after treatment of the resultant ate-complexes with BF3 OEt2. The R-methoxydiisopinocampheylboranes are prepared by reacting (-)-diisopinocampheylborane, derived from (+)-a-pinene, or (+)-diisopinocampheylborane, derived from (-)-a-pinene, with methanol. 

The reaction of the (Z)-crotyldiisopinocampheylborane derived from (+-)-a-pinene with aldehydes at -78 °C, followed by oxidative workup, furnishes the corresponding j yn-P-methylhomoallyl alcohols with 99% diastereoselectivity and 95% enantioselectiv-ity. Use of (Z)-crotyldiisopinocampheylborane derived from (-)-a-pinene also produces 5yn-alcohols with 99% diastereoselectivity but with opposite enantioselectivity, an example of reagent control. 

Composition According to ISO [19], the oil contains 86-95% E-anethole, up to 1.0% Z-anethole and up to 6.0% methyl chavicol. Eoeniculin can occur up to 3.0%, anisic aldehyde is limited to 0.5%. Further constituents are monoterpenes like a-pinene, a-phellandrene, limonene, linalool and a-terpineol. Besides P-caryophyllene, two further sesquiterpenes are typical trace components for Chinese star anise oil, namely E-and Z-a-bergamotene. 

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