Richard Besselievre

Proconvulsant effects in baboons of β-carboline, a putative endogenous ligand for benzodiazepine receptors

beta-Carboline-3-carboxylic acid ethyl ester (beta-CCE) was tested on two models of epilepsy in the baboon: kainic acid-induced limbic status epilepticus and photosensitive epilepsy. Beta-CCE, at very low doses ranging from 8 to 100 microgram/kg (i.v.), induced a reactivation of the limbic focus and photomyoclonic and generalized seizures in photosensitive and non-photosensitive baboons. The proconvulsant effect of beta-CCE may be associated with its binding to a particular subclass of benzodiazepine receptors.

SYNTHESES IN THE ELLIPTICINE-OLIVACINE SERIES: A POSSIBLE BIOGENETIC MODEL

The syntheses of the antitumor alkaloids ellipticine 5 and olivacine 4 have been achieved according to a general scheme based on the acid catalysed fragmentation of desethyl-uleine 14 into the carbazole 15. In the initial study, 15 was synthesised from l-benzenesulfonyl-2-lithio-indole and 4-formyl pyridine in 10 steps. A notable improvement was made with the preparation in high yield of 15 in a one-pot reaction between indole and the Δ3 piperidine 20. The missing carbon atoms were introduced according to a Bischler reaction on 15 to yield olivacine 4 after demethylation and aromatisation. Ellipticine was obtained in the same way from 23.

2-cyano Δ3 piperidines III: Total synthesis 0f (±) 20-epiuleine☆

The total synthesis of the indole alkaloid (±) 20-epiuleine has been achieved starting from indole itself and the appropriate 2-cyano Δ3 piperidine 7.

2-Cyano Δ3 piperideines VIII : Biomimetic approach to the synthesis of the decahydroquinoline ring system of poison-dart frog toxins

Abstract A biomimetic approach towards the synthesis of pumiliotoxin C has been developed. The key transformation of enamine equivalent 8 to 9 was catalyzed by contact with alumina. Cyclized intermediate 9 was then reduced stereospecifically to the trans decahydroquinoline 11 or stereoselectively to the cis compound 12 .

A short and efficient synthesis of phenolcar☐amides

Abstract The selective acylation of primary amine functions of polyamines with acylating agents derived from unprotected mono or o-dihydroxy aromatic acids is described. The key step of the method is the transient protection of the phenol groups during the preparation of hydroxyl-1-piperidine active esters. This method is especially applicable to the preparation of the radiolabelled polyamine derivatives.

Syntheses in the ellipticine-olivacine series

The syntheses of the antitumor alkaloids ellipticine 5 and olivacine 4 have been achieved according to a general scheme based on the acid catalysed fragmentation of desethyl-uleine 14 into the carbazole 15. In the initial study, 15 was synthesised from l-benzenesulfonyl-2-lithio-indole and 4-formyl pyridine in 10 steps. A notable improvement was made with the preparation in high yield of 15 in a one-pot reaction between indole and the Δ3 piperidine 20. The missing carbon atoms were introduced according to a Bischler reaction on 15 to yield olivacine 4 after demethylation and aromatisation. Ellipticine was obtained in the same way from 23.

Novel synthesis of the indole alkaloid ellipticine

A novel synthesis of the indole alkaloid ellipticine is described, the last step of which follows a possible biogenetic pathway.

SYNTHESES IN THE ELLIPTICINE-OLIVACINE SERIES: A POSSIBLE BIOGENETIC MODEL††Preliminary communication of part of this work: R. Besselièvre and H.-P. Husson, Tetrahedron Lett 1873 (1976). The work described comprises part of the Ph.D. Thesis of R. Besselievre (University of Paris-Sud, 1977).

The syntheses of the antitumor alkaloids ellipticine 5 and olivacine 4 have been achieved according to a general scheme based on the acid catalysed fragmentation of desethyl-uleine 14 into the carbazole 15. In the initial study, 15 was synthesised from l-benzenesulfonyl-2-lithio-indole and 4-formyl pyridine in 10 steps. A notable improvement was made with the preparation in high yield of 15 in a one-pot reaction between indole and the Δ3 piperidine 20. The missing carbon atoms were introduced according to a Bischler reaction on 15 to yield olivacine 4 after demethylation and aromatisation. Ellipticine was obtained in the same way from 23.