J.P. Zahra

Synthesis of ambergris fragrance chemicals from sclareol, involving palladium catalysed key steps

Abstract Ambraoxide, Ambrox ®, methylambraoxide and ambracetal are synthetised via key steps involving respectively a palladium acetate catalysed elimination and a PdCl 2 (CH 3 CN) 2 catalysed isomerisation of the mixture of sclareol and episclareol acetates.

Preparation d'acyl-4 methylene-3 tetrahydrofuranes: Un access aux α-methylene γ-lactones et butenolides fonctionnalises

Abstract The cohalogenation of α,β-unsaturated ketones 1 (a–j) by NBS in propargyl alcohol affords α-halo β-alcoxyketones 2 (a–j). Radical cyclisation of compounds 2 (a–j) gives rise to 4-acyl 3-methylene tetrahydrofurans 3 (a–j), according to a regio and diastereoselective process.

Cohalogenation de cetones α, β-ethyleniques dans le THF

Abstract Chlorination of α, β-unsaturated ketones 2 a–e at −80°C in THF gives rise exclusively to cohalogenation products 3 a–e. The reaction is regiospecific.

Insertion intramoléculaire et régiosélective de carbene. préparation de composés du type tétracyclo[4.2.0.02.8.O4.7]octane

Abstract Intramolecular carbene insertion reactions leading to tetra[4.2.0.02.8.04.7]octanes are discussed.

Détermination de la structure et de la stéréochimie de dehydroindanes trisubstitués par R.M.M. bidimensionnelle.

Abstract The structure elucidation of trisubstituted indanes by 2-D N.M.R. techniques is described and is used to determine the mechanism of their formation.

Synthèse régio et st'eréosélective de dehydroindanes trisubstitutés

Abstract Intramolecular Diels-Alder cyclization of readily available polyenes leads to regio- and stereoselective synthesis of dehydroindanes derivatives.