Josiane Beauhaire

IDENTIFICATION AND SYNTHESIS OF SORDIDIN, A MALE PHEROMONE EMITTED BY COSMOPOLITES SORDIDUS

Abstract The diastereoselective synthesis of (1S∗, 3R∗, 5R∗, 7S∗) 2,8-dioxa 1-ethyl 3,5,7-trimethyl bicylo [3,2,1] octane 1d has been achieved using as key-step the regioselective Baeyer-Villiger reaction of 2,6-disubstituted cyclohexanone. It confirms the identification of a new male pheromone emitted by the banana weevil, Cosmopolites sordidus. The trivial name sordidin is proposed.

Dimeric sesquiterpene lactones : Structure of absinthin

Abstract Absinthin, a constituent of A . absinthium , has been given structure 2 .

On the regioselectivity of the Baeyer-Villiger reaction of 2,6-dialkyl cyclohexanones: Application to the synthesis of sordidin, a male pheromone emitted by Cosmopolites sordidus

Abstract The diastereoselective synthesis of (1S ∗ ,3R ∗ ,5R ∗ ,7S ∗ )-2,8- dioxa-1-ethyl-3,5,7-trimethylbicyclo[3.2.1]octane ( 1d ) has been achieved using as the key step the regioselective Baeyer-Villiger reaction of 2,6-disubstituted cyclohexanone.

Preparation of stable 1,4-dihydropyrazines

The N-phenacylarylamine (4) gives the N,N-diphenacyl derivative (5) on treatment with phenacyl bromide under phase-transfer catalysis conditions. Condensation of (5) with an arylamine results in the formation of the thermally stable 1,4-diaryl-3,5-diphenyl-1,4-dihydropyrazine (6) in moderate yield. 1,2-Diaryl-3,6-diphenyl-1,2-dihydropyrazine (9) is obtained by heating N-phenacylarylamine (4). Formation of (9) is also promoted by a Lewis acid at lower temperature.

Structure of absintholide a new guaianolide dimer of Artemisia absinthium L.

Abstract Absintholide 1 is a new guaianolide dimer whose structure and stereochemistry has been elucidated on the basis of high resolution n.m.r.

Dimeric sesquiterpene lactone. Structure of isoabsinthin acid isomerization of absinthin derivatives

Isoabsinthin 2 is a new diguaianolide constituent of A.absinthium 1. The acid isomerizations of several derivatives of absinthin have been studied.

An Epoxide Derived from D-Glucose as the Key Intermediate for Penaresidine and Sphingolipids Synthesis

Abstract A multigram-scale synthesis of 3R,4R,5R 3,5-dibenzyloxy-4-p-methoxybenzyl-1,2-epoxypentane and its use as intermediate for sphingolipids, penazeridine and penazetidine synthesis are described.

Crystal structure of the dimer of 1,2-dehydroisophotosantonic lactone

Abstract The structure of the dimer 3 of 1,3-dehydrophotosantonic lactone 2 was established by X-ray diffraction analysis.

Structures of the artabsinolides; photo-oxygenation studies on artabsin

The structure and stereochemistry of four new guaianolides from Artemisia absinthium, named artabsinolides A, B, C, and D, have been established. They were synthesized via rearrangement or reduction of the endo-peroxides resulting from dye-sensitized photo-oxygenation of the main constituent of the plant, artabsin (1).

Synthesis of Diaprepal A2 Cadinane Analogs; Efficient Access to Polyoxygenated Cadinanes

Abstract Synthesis of the cadinane skeleton using Robinson annelation as key step is described; the use of the α-hydroxy methylene derivative of dihydro carvone allowed a good control of the regiochemistry of the reaction; synthesis of2b and 2c is possible using carvone as starting ketone; generalization of this procedure to epoxide 15 is also described leading to polyoxygenated cadinanes.