Martine Taran

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.

New Retinoid Analogs from δ-Pyronene, a Natural Synthon

δ-Pyronene (1), a readily available terpenic synthon, is an excellent raw material for the preparation of numerous terpenic intermediates. Original retinoid analogs such as “iso”-retinyl acetate (5), “iso”-retinal (6) and ethyl “iso”-retinoate (7), in which the cyclogeranyl moiety is functionalized in an unusual position, were prepared from δ-pyronene.

Part. IV - Obtention de nouveaux squelettes diterpeniques tetracycliques lors d'isomerisation d'epoxydes-8,9 diterpeniques

Abstract The action of borontrif luoride etherate on diterpenic-8,9 epoxides has been studied. We report a rearrangement of tetrasubstituted epoxide leading to new tetracyclic diterpene skeletons. The nature of the bicyclo[3.2.1] octane moiety constituting the C/D ring system means that these new compounds could be related to stemodane and stemarane diterpenes. These rearrangements could provide a chemical test for the biosynthesis of aphidicolin derivatives.

New Preparation Methods for α‐Damascone, γ‐Damascone, and β‐Damascenone using Pyronenes

Abstract γ‐ and δ‐Pyronenes are terpenic synthons easily available from myrcene. They are used as intermediates in the synthesis of α‐damascone, γ‐damascones, and β‐damascenone.

Synthese et rearrangement de l'epoxy-8,14β pimarate de methyle en vue d'acceder au squelette diterpenique cassane

Abstract Methyl-8,14 β-epoxypimarate is stereoselectively obtained from pimaric acid via a stereocontrolled epoxidation of methyl-15 hydroxy-16-nor pimarate. The isomerisation of this epoxide with Lewis acid and on silica gel has established the existence of new rearrangements of the diterpene skeleton leading to bicyclic diterpene compounds by a Grob fragmentation and to one cycloditerpene compound.

Epoxides from Myrcene: New Versatile Tools for the Synthesis of Functionalized Acyclic Terpenoids

Abstract Mono-epoxides prepared from myrcene, were used as synthetic intermediates to obtain citral, linalool, geranylacetone and pseudo-ionone.

Epoxides from Myrcene: Selective Obtention

Abstract 1,2-and 3,10-epoxy myrcene are selectively obtained from dihydroxy derivatives prepared by an oxidation reaction of myrcene with potassium permanganate.

Part. III - Rearrangements d'epoxydes-7,8 diterpeniques catalyses par l'etherate de trifluorure de bore

Resume The action of borontrifluoride etherate on methyl sandaracopimarate and pimarate-8,14 epoxides has been studied. A backbone rearrangement and the obtention of compounds with new skeletons are reported.

Diterpenic skeleton transformations : alumina catalysed rearrangements of epoxides

Abstract The 8,14 β-epoxide of methyl sandaracopimarate undergoes new rearrangements on contact with active alumina, yielding labdane and another compound having the cycloisopimarane skeleton.

Synthèse de nouveaux intermédiaires d'analogues rétinoı̈des à partir du δ-pyronène

Resume Le delta-pyronene, un synthon terpenique industriellement disponible, est une matiere premiere utilisee dans la synthese de nouveaux intermediaires d’analogues de retinoides tels que l’aldehyde iso-beta-C14, l’iso-beta-ionylidene acetaldehyde, la cetone iso-beta-C18 et l’iso-beta-ionylidene acetate d’ethyle.