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A hydrodistilled oil from Corymbia citriodora Hook. produced from leaves harvested in the Reunion Island was analyzed by GC and GC/MS on nonpolar and polar columns, respectively. Nearly 100 constituents were identified. The major constituents were citronellal (63.6%), α-citronellol (7.3%), isopulegol isomers (6.5%), citronellyl acetate (2.6%), p-cymene (2.5%), citronellal dimmers (2.5%), α-pinene (2.1%) and β-caryophyllene (1.2%). Several esters of isobutyric acid (4), monoterpene- (18), and sesquiterpene (15) hydrocarbons, oxides (6), monoterpene alcohols (10), esters (8) and aldehydes (4), (Z)-jasmone, citronellyl citronellate, citronellic acid, eugenol, and some aliphatic and alicyclic derivatives, were presented in trace amounts. On the polar column, further constituents were identified, including menthone, isomenthone, 4-vinylguiacol, and two heavy aliphatic acids: myristic and palmitic acids.

Essential oils from leaves of cypress cultivated in France that originated from various geographic origins were analyzed by GC/MS. In total 120 constituents were characterized, from which 46, 57, 52, 57, 59, 67, and 58 compounds were found in the oils of Cupressus atlantica Gaussen, C. cashmeriana Royle, C. chengiana Hu, C. duclouxiana Hickel, C. funebris Endl., C. guadalupensis S. Wats, and C. macnabiana A. Murr., respectively. The main components of the oils were found to be: α-pinene and δ-3 carene for C. atlantica Gaussen; α-pinene and sabinene for C. cashmeriana Royle, C. chengiana Hu and C. funebris Endl.; α-pinene and α-cadinol for C. macnabiana A. Murr; α-pinene, terpinen-4-ol and a sesquiterpene for C. guadalupensis S. Wats; limonene and α-cadinol for C. duclouxiana Hickel.

The synthesis of 2-mercapto-p-menth-8-ene (3) and 1-mercapto-p-menth-8-ene (4) are described, starting, respectively, from thioepoxydation of (+)-trans-limonene 1,2-epoxide (1a) and (+)-cis-limonene 1,2-epoxide (1b) via hydride reduction of episulphides 2a and 2b. Structural determination of these sulphur-containing terpenoids was achieved by one- and two-dimensional NMR spectroscopy. The odours of these two new monoterpene thiols were described, respectively, as reminescent of grapefruit juice and as being typically alliaceous. Copyright © 2002 John Wiley & Sons, Ltd.

The selective oxidation reactions of thiazolidines were studied. The synthesis of 2- and 3-thiazolines, as well as that of thiazoles, thiazolidine-1-oxides and thiazolidine-1,1-dioxides, are presented. Olfactory analysis of several of these compounds reveals interesting notes with thresholds in the ppm range, in most cases related to foodstuffs. Copyright © 2002 John Wiley & Sons, Ltd.

Photochemical acetylthiolation of (-)-sabinene 1 afforded 10-acetylthiothujane 2 and an unexpected cyclopentenyl methyl thioacetate 3 in moderate yield (24%). Hydride reduction of these two latter compounds gave two monoterpenoid thiols ( 2a and 3a ) in excellent yield (95%). The odour of the major sulfur-containing compounds 2 and 2a was respectively described as being typically anisic and as reminiscent of cooked leek. Structural determination of these derivatives was achieved by one- and two-dimensional NMR spectroscopy.

Photochemical thioacetylation of (s−)- i -cadinene 1 afforded 5-acetylthio-cadinene 1a which was further reduced into 5-mercapto-cadinene 1b in good yield (80%). Thioepoxydation of trans -1,10-cadinene oxide 1c , prepared from m -CPBA oxidation of 1 , was also investigated. Structural determination of these derivatives was achieved by one- and two dimensional NMR spectroscopy.

3-Propyl-γ-sultine has been identified for the first time in extracts of yellow passion fruit (Passiflora edulis f. flavicarpa). The chemical structure of this new molecule was confirmed by synthesis. Some other analogues were prepared using a general and efficient method. A biosynthetic pathway involving the presence of 3-sulphanylhexanol as a precursor is proposed. In addition, the chirality of the natural sultine has been evaluated by chiral gas chromatography. Copyright © 2002 John Wiley & Sons, Ltd.

Volatile compounds from guava (Psidium guajava L.) were extracted using dichloromethane. Among these volatile compounds, methyl 2-methyl-thiazolidine-4-(R)-carboxylate (cis and trans) and the ethyl 2-methyl-thiazolidine-4-(R)-carboxylate (cis and trans) could be identified for the first time in fruits. The chemical synthesis of the reference compounds and other analogues allowed the further comparison with the guava extracted thiazolidines. The absolute configuration of the cis/trans isomers was determined by nuclear magnetic resonance (1H-NMR) and by nuclear overhauser enhancement (2D NMR NOESY). Copyright © 2001 John Wiley & Sons, Ltd.

Volatile constituents from wild Calamintha nepeta (L.) subsp. nepeta harvested in the autumn in the vicinity of Marseilles were analyzed by GC and GC/MS on nonpolar and polar columns, respectively. Among the 120 identified compounds, the 11 major constituents were: menthone (52.7%), pulegone (9.1%), piperitone (7.8%), neomenthol (7.6%), menthol (4.3%), limonene (4.0%), isomenthone (1.7%) and 3-octanol (1.6%). Several esters of isovaleric and 2-methylbutyric acids, 14 monoterpenes and 8 sesquiterpenes (hydrocarbons), and many other compounds were present in trace amounts including piperitone oxide, and piperitenone oxide. By comparison with other chemotypes, viz., C. nepeta ssp. glandulosa, described in the literature, our sample belongs to the menthone/pulegone chemotype which is the most common one.

The synthesis of a series of 2-thiazolines was carried out under mild conditions from the corresponding thiazolidines, by a Ru-catalyzed/TBHP oxidation reaction conditions. The reaction was chemoselective towards the amine-imine oxidation and was also regioselective, affording the unsaturation at the 2-position of the heterocycle, even with thiazolidine substrates bearing ester groups at the 4-position.

Kinetic resolution of racemic e-lactones by Pig Liver Esterase give optically active R (+) e-lactones. When alkyl group is higher than propyl. Horse Liver Esterase leads to the destruction of the opposite enantiomer. Enantiomeric excess is easily evaluated by G.C. on a chiral stationary phase.

The synthesis of a series of allyl substituted 3-thiazoline-carboxylates was carried out from the corresponding thiazolidines, by a MnO2-mediated oxidation reaction under mild conditions. The reaction was chemoselective towards the amine–imine oxidation and was also regioselective, affording the unsaturation at the 3-position of the heterocycle.

The synthesis of a series of 2-thiazolines was carried out under mild conditions from the corresponding thiazolidines, by a Ru-catalyzed/TBHP oxidation reaction conditions. The reaction was chemoselective towards the amine-imine oxidation and was also regioselective, affording the unsaturation at the 2-position of the heterocycle, even with thiazolidine substrates bearing ester groups at the 4-position.

The synthesis of a series of allyl substituted 3-thiazoline-carboxylates was carried out from the corresponding thiazolidines, by a MnO2-mediated oxidation reaction under mild conditions. The reaction was chemoselective towards the amine–imine oxidation and was also regioselective, affording the unsaturation at the 3-position of the heterocycle.

A pentanal and diethyl maleate mixture (concentration ratio 51) is irradiated with a frequency tripled Nd-YAG laser (355 nm) in the peak interval 1.5KW.cm−2 – 8.75MW.cm−2. Diethyl pentanoyl succinate is formed selectivity by chain addition reaction with an intensity dependant quantum yield which can reach 2000%.

Chromatographic profiles transformed into stick profiles allow us to access the recognition and the global identification of Complex Mixtures within constituted Complex Compositions of several mixtures. We have conceived a database of automatic research of Complex Mixtures.

Morphology recognition of enantiomeric structures are differentiated by chiral stationary phase. Effects of substituent and behavior of various families of racemics, esters of secondary alchohols, γ and e lactones, are examined. In a homologous series it becomes possible to predict retention data.

Isomerization of 3-pentyl-5-methyl-1,2-oxathiolane-2-oxide in the presence of iodine is described. A mechanistic pathway which involves a ring-opening reaction by cleavage of the CO bond with or without epimerization at the sulfur atom is proposed, consistent with the stereochemical investigations.

Pure pentanal is irradiated with a frequency tripled Nd-YAG laser in the intensity interval 0.1-1 MW. cm −2 . Alpha-dione and α-ketol are formed selectively with quantum yields of 5.5 and 38%, respectively. As only the S 1 state of the pentanal is excited, the results obtained are explicable as a dynamic effect in connection with the order of the reactions.

Behaviour of stationary phases. I. Linear relationships between retention data of benzene derivatives Retention times of about 140 benzenic mono- and polysubstituted compounds have been determined on a collection of stationary phases under isothermic conditions. The “numerical taxonomic aggregation” methods applied to these data lead to a classification of the stationary phases, in accordance with a measure of association between pairs of variables and an amalgamation rule for clustering. Three classes of phases (polar, non-polar and polyfluorinated) appear on the dendogram. Using the retention data relative to two phases, ϕ 1 and ϕ 2 , we show that a linear relationship between the two series of data is obtained whenever the two phases belong to the same cluster. This relationship (where coefficients a and b are constant in relation to Z, but vary with φ, ϕ 1 , ϕ 2 and T ) constitutes a general model, applicable to all benzenic compounds (mono-, di- or trisubstituted) under examination. The diversity of experimental conditions in the determination of retention data led us to a general updating of the various ways of expressing the retention, by simultaneously studying the effects of the temperature T and/or those of the nature of the stationary phase ϕ. We obtain a linear relationship in which Gr 1 and Gr 2 are either retention indexes, retention volumes or retention times, and Sq represents any carbon skeleton bearing the function Z. Such a relationship permits the comparison of interlaboratories results. Thus, although the characteristics of the columns and the experimental conditions vary, we obtain very satisfactory linear relationships between our own data expressed as log (reduced time) and those from the literature expressed either as indices or as log (retention volume) for stationary phases belonging to the same taxonomic class.

In chromatographic studies polar effect constants σ*c, similar to those of Taft and Ingold, can be obtained from an empirical additivity relationship which takes into account three structural increments.

Chromatographic behaviour of stationary phases. II. Application of factor analysis A “principal component analysis” applied to a set of retention times of 17 benzenic monosubstituted compounds on a collection of 21 stationary phases, leads to the following relationship: Knowing the experimental data , and of any substance P, measured on three phases, o 1 , o 2 and o 3 (respectively non-polar, polyfluorinated and polar) one can estimate the gas—liquid chromatographic retention data , of the same substance P on any stationary phase o i with the aid of the above relationship ( a o , b o , c o , and d o are the coefficients of the non-restricted multiparametric relationship.)

Laser irradiation of R(–) carvone in solution in acrylonitrile within the absorption band of its n−π* transition (≃350 nm) leads to the formation of cyclobutanic adducts, together with traces of camphocarvone.The carvone transformation is complete and appears with high quantum efficiency. The quantum yield for intermolecular reaction is intensity dependent (13–30%). This is ascribed to the fact that the reaction takes place via both a one and a two-photon absorption channel, the second being even more efficient.

lComparison of stationary-phase classification scales Comparison of the stationary-phase classifications demonstrates their relation to the nature of the forces interacting between the solvent and the solute. The ?* factor, which expresses the intensity of the chromatographic interaction, seems to be the most satisfactory basis for classification at present.

Behaviour of ethers. VII. Principle of determination of the polar effect constants It is pointed out that the simplified linear extrathermodynamic relationship where retention data are plotted versus the polar factor and the number of ramifications located on the first carbon atom neighbouring the chemical function, leads to a satisfactory result. This relationship may be used for enlargement of the σ* scale, when applied to chromatographic phenomena. On the other hand, enlargement of this scale can be carried out by incrementation.

Behaviour of ethers. I. Working out a “Taft”-like equation founded on retention data of saturated ethers Variations in retention data of a series of saturated aliphatic ethers have been studied with a view to express them in a Taft-like equation. The linear relationships pointed out show the influence of the ramifications located on the atom neighbouring the oxygen. The numerical values of ϱ * are determined for six stationary phases. They express the selectivity of the stationary phases towards the ethers and they can be considered as an evaluation of the polarity of these substances.

L'etude de la variation du logarithme du temps de retention reduit relatif d'une serie d'allyloxyalcanes et de phenoxyalcanes est abordee a l'aide de la methode de topologie-information DARC, de sorte que les relations types obtenues tinnent compte de la contribution de chacun des atomes de carbone des groupements alkyles variables. De plus, ces relations elargissent le domaine de validite de la loi de James-Martin aux molecules ramifiees.

The surface tension of mint, lemon and orange oils and the interfacial tension of these oils against water were investigated by the Wilhelmy plate method. Variation of these tensions as well as variation of the surface tension of waters after prolonged contact with the oils were measured as a function of time and temperature. Spreading coefficients Sow calculated from these data show that the spreading tendency of these oils, in the temperature range 30–50°C, is in the order: orange oil > lemon oil > mint oil. Combined gas chromatography and mass spectroscopy analytical data reveal a high concentration of mint oil constituents in water equilibrated with this oil. Adsorption of these surface-active species at the air/water interface considerably lowers its surface tension. Positive temperature coefficients of the surface tension of this water and of the mint oil/water interfacial tension are attributed to the change in chemical composition occurring at these interfaces during heating. Lowering of the interfacial tension at orange oil and lemon oil/water interfaces was observed when these interfaces were heated. This may be attributed to the interfacial adsorption of 8-p-menthene-1,2-diol present in the waters equilibrated with orange and lemon oils. The data obtained may be indicative of phenomena observed during encapsulation of these essential oils by the complex coacervation procedure.

The photoaddition of acrylonitrile to mesityl oxide was accomplished at 355 nm with high quantum yield (15%) using a pulsed laser (intensity= 9 MW/cm 2 , pulse duration 13 ns, repetition rate= 10Hz) and selectively led to three products in contrast to irradiation with a mercury lamp which principally gave an acrylonitrile polymer and with continuous wave laser (intensity= 5.7 W/cm 2 ) which gave a much lower quantum yield (0.4%).

Application of a Taft-type equation to retention data. Additivity of substituent effects The previously established linear extrathermodynamic relationship can be applied to a chemical population the common functional group of which is characterized by an axis of symmetry. In all other cases it is possible to differentiate the particular contribution of each alkyl group Rl; consequently their effects must then be considered separately.

With the final aim of predicting chromatographic retention data, a population of mono- and poly-functional benzenes was subjected to diverse methods of multivariate analysis. Numerical taxonomic aggregation indicated three clusters of stationary phases, the polyfluorinated ones behaving very differently from the polar or non-polar phases Factor analysis was largely successful for the g.l.c. data prediction; the method is based on a multiparametric regression model.

Satisfactory reproduction of the retention data matrix in the case of a series of mono-substituted benzenes and a series of aliphatic substances proves the general character of the prediction equation where x Q i , φ j are the retention data x of unknown solute Q i on phase φ j ; a Q i , b Q i , c Q i and d Q i are regression coefficients which to some extent account for forces of orientation, charge transfer and association; and x ST i , φ j are independent variables representing the retention data of the four compounds of the standard set of substances on a given phase φ j . These four compounds are selected by diverse methods of multivariate analysis. The predicted values show very satisfactory agreement with the observed values.

In order to predict retention data in gas-liquid chromatography, extension of the Taft scale of σ * polar effect constants is essential and can be carried out by means of the equation log t ′ R = ρ * σ * + h ( n H -3). Using retention data of alcohols, σ * of 42 substituents have been estimated, giving rise to a σ * c scale appropriated in the field of chromatography.

The acidic fraction of benzenic extract of Blackberry bud (Ribes nigrumL.) show a diterpene acid identified as hardwickiic acid by IR., UV., RMN. and SM.

The photoaddition of acrylonitrile to mesityl oxide was accomplished at 355 nm with high quantum yield (15%) using a pulsed laser (intensity= 9 MW/cm 2 , pulse duration 13 ns, repetition rate= 10Hz) and selectively led to three products in contrast to irradiation with a mercury lamp which principally gave an acrylonitrile polymer and with continuous wave laser (intensity= 5.7 W/cm 2 ) which gave a much lower quantum yield (0.4%).

1,2-Epithiocyclohexane was obtained selectively by irradiation of a mixture of cyclohexene and sulphur with a pulsed laser (266 nm).