E. Montaudon

Phase-Transfer Catalytic Alkylation of Hydroperoxides: A Convenient Route to Mixed Dialkyl Peroxides

Abstract The solid-liquid phase transfer catalytic alkylation of hydroperoxides using solid potassium hydroxide as a base and TEBAC as a phase transfer catalyst is reported. When the alkylating agent is a primary bromide, this reaction represents a simple and quick method for the synthesis of mixed dialkyl peroxides in fair yields.

Intramolecular homolytic displacements 7 — Free radical additions to unsaturated peroxy compounds : Synthesis of oxygenated heterocycles

Abstract Free radical additions of hydrogen donor solvents to tert-butyl perpent-4-enoate have given 4-substituted γ-butyrolactones, with yields of 50 % or greater. Such reactions applied to allyl-tert-butyl peroxide have produced 2,3-epoxypropanation of these solvents. Similar addition-elimination processes occurred with tert-butyl 4-methyl-perpent-4-enoate, tert-butyl 2,2-dimethyl-perpent-4-enoate and tert-butyl-methallyl peroxide, but they failed with tert-butyl 5-methyl-perhex-4-enoate and tert-butyl-3-methyl-but-2-enyl peroxide.

Fonctionnalisation des γ- et δ-pyronènes. Synthèse et étude de la réactivité des composés peroxydiques

Resume La photooxygenation des γ- et δ-pyronenes, realisee pour la premiere fois, conduit classiquement a un hydroperoxyde, un hydroperoxy-peroxyde, et un endoperoxyde respectivement. La reactivite de ces peroxydes est etudiee. Ils conduisent a des composes mono-, di-, voire trifonctionnels, la plupart inedits, pouvant constituer des bases de depart pour la synthese de molecules a potentialite olfactive ou therapeutique.

Epoxyesters p-menthaniques et pinaniques en milieu basique – Parfum de noix de coco

Base-Induced Reactions of p-Menthane- and Pinane-Derived Epoxyesters – Coconut Fragrance The base-induced isomerization of p-menthane- and pinane-derived epoxy esters was studied. The reaction is dependent on the structure of the terpene compound, the nature of the base, and experimental conditions. Among all the new synthesized compounds, one, 6a, emits a very strong fragrance of coconut. In the structure of this tricyclic lactone, the presence of a methyl substituent is essential.

Isomérisation d'époxypinanes fonctionnels en milieu basique

Abstract Functional pinocarveols and bifunctional spiropinanes could be prepared by basic isomerisation of 2,3-epoxypinanes bearing a function or a functional chain on the carbone 10. Preliminary results are presented, which illustrate a general synthesis of these new compounds.

Induced Decomposition of Peroxycompounds in Synthesis: Free Radical Functionalization of Crown Ethers

Free radical additions of commercial 12-crown-4, 15-crown-5 and 18-crown-6 to various unsaturated peroxyesters and peroxides allowed their functionalization: acetonyl, 2, 3-epoxypropyl, 2-oxacyclopentylmethyl, 3-oxo-2-oxacyclopentylmethyl and 3-oxo-2,4-dioxacyclopentylmethyl groups were grafted onto the heterocycle. Polyfunctionalization could be obtained by changing the ratio crown ether/peroxycompound.

Isofenchylic alcohol derived from a functionalized pinene oxide: unexpected formation and structural confirmation using multi-dimensional NMR spectroscopy and x-ray crystallography

The complete proton and carbon‐13 assignment and the stereochemistry of (1R)(7S)(9R)(11S)‐11‐hydroxy‐8,8‐dimethyl‐6‐oxa‐5‐oxo‐3‐thiatricyclo[7.2.1.01,7]dodecane, a fenchylic derivative compound, was performed by using 1D and 2D NMR experiments (COSY, HMBC, HMQC, NOESY) leading to its unambiguous structural characterization. This structure was confirmed by an x‐ray crystallographic experiment. Copyright

Competing β-scission and hydrogen transfer to the pinanyl radical in the addition of methyl thioglycolate to β-pinene derivatives

Despite previous reports to the contrary, addition of methyl thioglycolate to β-pinene always leads to both pinane and p-menthene adducts, the proportion of the latter increasing with the reaction temperature. This is attributable to the substantially higher activation entropy for β-scission than for hydrogen transfer, while the activation enthalpy is higher for the latter reaction. Any substituent at the 3-carbon of β-pinene, trans with respect to the gem-dimethyl bridge, increases the p-menthene yield: polar effects of the mainly electron-withdrawing substituents appear to disfavour hydrogen transfer to the tertiary pinanyl radical and favour β-scission. Analysis of the temperature dependence of the pinane∶p-menthene ratio for the substituted β-pinenes indicates that variations in the activation entropy difference for the two reactions are at least as important as those of the activation enthalpy.

“One-Pot” Synthesis of Disymmetrically α,α′-Disubstituted Succinic Anhydrides Precursors

Abstract A “one-pot” synthesis for disymmetrically α,α′-disubstituted succinic anhydrides precursors is reported in the present paper. Substituents are aryl, primary or secondary alkyl groups. This reaction represents a simple and quick method with fair yields.

Intramolecular homolytic displacements. Part 18. Stereochemical effects of the induced decomposition of unsaturated peroxidic compounds leading to the formation of five-membered rings

Free-radical additions of methylene dichloride and chloroform to various peroxidic compounds having unsaturation δ to the peroxidic bond and a substituent on the chain linking both functions gave five-membered heterocycles with some stereoselectivity. The influence of various structural factors such as the size of the substituent, the nature of the peroxidic function (peroxide, perester and percarbonate), etc. have been studied.