Bernard Delmond

Analysis of the variation of the essential oil composition of Eucalyptus globulus Labill. from Portugal using multivariate statistical analysis

Abstract Samples of Eucalyptus globulus Labill. subsp. globulus essential oil obtained from trees of different ages, growing in maritime and inland Portuguese regions, collected in May and November periods (1991–1992), were submitted to quantitative analysis. The results obtained were interpreted using principal component analysis and cluster analysis, considering the 25 abundantly found compounds. These compounds were grouped according to their variation patterns, leading to the definition of five groups, four of which have shown to be significant in the differentiation of young and adult leaves. Young leaves, when compared to adult leaves, were found to have higher oil yields, with lower percentage of group II (in which 1,8-cineole is included) and III compounds and higher percentages of compounds from groups I and IV. Variations in the oil composition due to season and geographic localisation were found not to be significant.

In situ generated, polymer-supported organotin hydrides as clean reducing agents

Abstract Polymer-supported organotin hydrides were generated in-situ from polymer-supported organotin halides and NaBH 4 . Their reducing ability was monitored by reaction with 1-bromoadamantane. The residual tin pollution was estimated by ICP-MS.

Halogénoalcoxyétains II. halogéno-3 alcoxytributylétains, synthéses et propriétés—application à la preéparation d'oxétannes et d'alcools stanniques

Abstract 3-Halogenoalkoxytributyltin compounds prepared from 1,3-halogenohydrins and tributyltin ethoxyde decompose at 200° leading to the corresponding oxetanes. This reaction is a very convenient method of preparation of this kind of heterocycles. The behaviour of 3-halogenoalkoxy tributyltin with magnesium was investigated: we observed in very good yields the formation of 3-hydroxyalkyltributyltin by an intramolecular process.

Catalytic and supported Barton–McCombie deoxygenation of secondary alcohols: a clean reaction

Abstract Secondary alcohols were deoxygenated using a new version of the Barton–McCombie process involving a catalytic amount of supported tin hydride in the presence of trimethoxysilane. The products are then easily separated from the catalyst by a simple filtration avoiding pollution by toxic tin by-products.

Un nouvel hydrure organostannique greffé sur support insoluble

Abstract A polystyrene-supported tin hydride was prepared from Amberlite XE305. The stannyl group was separated from the aromatic ring of polystyrene by four methylene units. The product contains 1.2 mmol active SnH/g polymer.

Part I. epoxydes diterpeniques : synthese et reactivite d'epoxydes derives d'acides resiniques

Abstract Epoxidation of methyl esters of resin acids with the pimarane skeleton with p-nitroperbenzoic acid has permitted the isolation of epoxides of the intracyclic double bond. Allylic diterpenic alcohols were obtained by acid-catalysed isomerisation of diterpene epoxides, and the action of Collins reagent on these allylic alcohols has been studied.

Halogénoalcoxyétains : I. (halogéno-2 alcoy)tributylétains, synthéses et propriétés. application á la préparation d'époxydes

Abstract 2-Halogenoalkoxytributyltin compounds have been prepared from tributylethoxytin and 1,2-halohydrins. The thermal degradation and its mechanism are investigated. These reactions offer a convenient way to prepare epoxides.

L'epoxy-pyronène : Synthon d'accès aux cyclocitrals et aux ionones et précurseur de nouveaux composés terpénoïdes

Abstract The selective obtention of epoxy-pyronene from δ-pyronene has been realized using metachloroperbenzoic acid. The isomerization of this epoxydic compound with Lewis and protonic acids and on active alumina has been studied leading to cyclocitrals. Ionones are obtained from epoxy-pyronene by homologation with various C 3 units, in the presence of paratoluenesulfonic acid in order to obtain β-cyclocitral in situ . New terpenic compounds with the cyclogeranyl skeleton were obtained from epoxy-pyronene by reduction followed by homologation.

Delta-pyrone`ne : Epoxydation se´lective et acce`s aux cyclocitrals

Abstract: The selective obtention of epoxides from delta-pyronene has been realized using a peracid and a cyclodehydrohalogenation reaction. The isomerization of an epoxidic isomer with Lewis and protonic acids and on active alumina has been studied leading to cyclocitrals.

Nouvelles Voies d'Accès aux Theaspiranes, Mégastigma-5,7,9-trién-4-one et Mégastigma-5,8-dién-4-one à Partir du γ-Pyronène

Resume γ-Pyronene, a terpenic synthon easily available from myrcene, an industrial raw material, is used as an intermediate in the synthesis of theaspiranes and various megastigmane derivatives. These compounds are useful in the preparation of perfumes and aromas.