Terpene aldehydes

This aldehyde has been isolated from various Eucalyptus oils by Baker and Smith. It has a pleasant odour resembling that of cumic aldehyde, with which Schimmel Co. have considered it to be identical. This, however, is improbable, and Baker and Smith consider it to have the formula CjHjjO, which would make it to be a lower homologue of the terpenic aldehydes. Its physical characters, however, are somewhat doubtful, as specimens isolated from the oils of Eucalyptus hemiphloia and Eucalyptus salubris show. These are as follows —... 

Properties of Latia luciferin. Latia luciferin is a highly hydrophobic, fat-soluble compound, and volatile under vacuum. It is a colorless liquid, with an absorption maximum at 207nm (s approx. 13,700 Fig. 6.1.2). The chemical structure of Latia luciferin has been determined to be 1 (C15H24O2), an enol formate of a terpene aldehyde 3 (Fig. 6.1.3 Shimomura and Johnson, 1968b). The enol formate group of Latia luciferin is unstable the luciferin is spontaneously hydrolyzed... 

Laboratory colonies of worker ants were fed sugar-water containing l-C14-acetate, 2-C14-acetate, or in a carefully controlled simultaneous feeding, 1-C14- or 2-C14-mevalonate. After an appropriate period, the ants were frozen and extracted with methylene chloride and the terpene aldehydes (citronellal and citral) isolated by thin-layer chromatography. These were then converted into their dini-... 

Among the acyclic terpene aldehydes, citral and citronellal hold key positions as fragrance and flavor chemicals, as well as starting materials for the synthesis of other terpenoids. Hydroxydihydrocitronellal is one of the most important fragrance materials. Derivatives of these aldehydes, particularly the lower acetals, are also used as fragrance materials. Acyclic sesquiterpene aldehydes are not very important as such, but they contribute to the characteristic fragrance and aroma of essential oils, for example, in the case of a- and /3-sinensal in sweet orange oil. 

Cyclic terpene aldehydes occur in essential oils only in low concentration. These aldehydes are seldom used as single fragrance substances. A few of the cyclic terpene ketones are commercially important as fragrance and flavor substances, for example, menthone and carvone, which have the / -menthane skeleton, and the ionones, which have a (trimethylcyclohexenyl)alkenone skeleton. The ionones and... 

The monoterpenes are subdivided into three groups acyclic, monocyclic and bicyclic (there is only one tricyclic terpene tricyclene). Each group contains hydrocarbon terpenes, terpene alcohols, terpene aldehydes, ketones, oxides etc... 

For syntheses of vitamin A aldehyde (retinal) and higher terpene aldehydes, appropriate 2-methyl-2-butene-1,4-dials (32) with a protected aldehyde function were used as the C5 building blocks. They are accessible, in turn, via the C5 building block p-formylcrotyl acetate (8 b) in the form of its dimethyl acetal, or via P-formylcrotyl methyl ether (29)34 b) ... 

Many terpenes contain additional functional groups, especially carboxyl groups and hydroxyl groups. A terpene aldehyde, a terpene alcohol, a terpene ketone, and a ter-pene acid are shown next. 

C25 terpene aldehyde) (fungal pathogens on rice maize) e-NFL), PfCDPK, Quercetin-stimulated intestinal CD secretion [phytotoxic]... 

PROP Expressed from the peels of Dancy and related varieties of Citrus reticulata Blanco. The components include d-limonene, n-octylaldehyde, n-decylaldehyde, citral, linalool, citronella, cadinene, terpenes, aldehydes, alcohols, and esters (FCTXAV 16,637,78). Red-orange to brown-orange liquid orange-like odor. Sol in fixed oils, mineral oil sltly sol in propylene glycol insol in glycerin. 

The formylation of metalated sp carbons, for example in a stannylbenzene (Eq. 185) [458] or in vinylsilanes [459,460] (Eq. 186), with Cl2CH(OMe) and TiCU, in which the ipso carbon to the stannyl or silyl group is selectively formylated, has been reported. The formylation of a vinylsilane was used in the preparation of a terpene aldehyde, nuciferal, as shown in Eq. (186) [461]. 

Asymmetric reduction of di-geranial, di-neral and related linear terpenic aldehydes can be achieved with LiAlH4-dihydroxybinaphthyl complex with 72-91% ee (Scheme 43). ° ... 

Citral, a fragrant terpene aldehyde made up of two isoprene units, is the main component of the steam-volatile fraction of lemon grass oil and is used in a commercial synthesis of vitamin A. 

Oxidation of tetraterpenes yields many compounds, and the cyclic compounds with a trimethylcyclohexane ring are easily associated with degradation of monocyclic and bicyclic carotenes, but allylic compounds are now as conspicuous in their biogenetlc origin. Many such compounds are derived from lycopene, phytoene and phyto-fluene, three very common acyclic carotenes. These allylic compounds are often identified only as terpene aldehydes and ketones and not as carotene degradation products (10). 

Table 4. Tyrosinase Inhibitory Activity of Acyclic Terpene Aldehyde and Acid at 100 (lg/ml...

This method has proved of special value in preparation of terpene aldehydes. To shift the equilibrium to the side of the desired carbonyl compound (Oppen-hauer), the concentration of the hydrogen-acceptor may be raised or its boiling point may be such that the aldehyde formed distils out of the mixture. 

According to Montedoro G. et al [12] and Tiscomia et al [3] different volatile constituents are found in virgin olive oil. They account for approximately 150 compounds of several chemical classes aliphatic and aromatic hydrocarbons, aliphatic alcohols, oxygenated terpens, aldehydes, ethers, ketones, thiophene and furane derivatives, esters (table 1) all these compounds confer on the virgin oil the characteristic aromatic notes. In particular C(> aldehydes and related alcohols (hexanale, cis-3-... 

Application of RCM to acrylates derived from terpene aldehydes containing a remote double bond yielded the 6-substituted dihydropyran-2-ones <01TL6069> and oxabicyclo-[3.2.1]octane undergoes an efficient ring-opening cross-metathesis with electron-rich alkenes to give unsymmetrically 2,6-disubstituted tetrahydropyran-4-ones <01OL4275>. 

Definition Oil expressed from the peels of Citrus reticulata] contains d-limonene, n-octylaldehyde, n-decylaldehyde, citral, linalool, citronella, cadinene, terpenes, aldehydes, alcohols, and esters... 

Mondello, L., K. D. Bartle, G. Dugo, and P. Dugo, 1994a. Automated HPLC-HRGC A powerful method for essential oil analysis Part III. TUiphatic and terpene aldehydes of orange oil. 

FIGURE 19.9 Reduction of terpene aldehydes and epoxidation of terpene alcohols by Streptomyces ikuta-manensis Ya 2 -1. (Modi ed from Noma, Y. et al., Reduction of terpene aldehydes and epoxidation of terpene alcohols by S. ikutamanensis, Ya-2-1, Proceedings of 30th TEAC, 1986, pp. 204-206.)... 

Noma, Y., E. Akehi, N. Miki, and Y. Asakawa, 1992a. Biotransformation of terpene aldehyde, aromatic aldehydes and related compounds by Dunaliella tertiolecta, 31 515 517. 

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