Marie-Elise Tran Huu Dau

Trigocherrin A, the first natural chlorinated daphnane diterpene orthoester from Trigonostemon cherrieri.

Trigocherrin A, a chlorinated and highly oxygenated daphnane diterpenoid orthoester (DDO), was isolated from the bark of Trigonostemon cherrieri. Trigocherrin A is the first example of a naturally occurring halogenated DDO. Its structure was elucidated by comprehensive analysis of NMR spectroscopic data, and its absolute configuration was determined by comparison of experimental and theoretically calculated ECD spectra. Trigocherrin A exhibited a potent and selective effect against Chikungunya virus in Vero cells.

Remarkable stereoselectivity in intramolecular Borono-Mannich reactions: synthesis of conduramines.

An unprecedented intramolecular Petasis condensation provides a novel approach to biologically important conduramines. The compounds are produced with an exclusive anti stereoselectivity for the newly created β-amino alcohol motif. The stereochemical outcome of the reaction is opposite to the one usually observed in the intermolecular reaction.

Goniomedines A and B: Unprecedented Bisindole Alkaloids Formed through Fusion of Two Indole Moieties via a Dihydropyran Unit

Two novel bisindole alkaloids, goniomedines A (1) and B (2), possessing an unprecedented quebrachamine-pleioarpamine-type skeleton, in which indole moieties are fused via a dihydropyran unit, were isolated from the stem bark of Gonioma malagasy. The structures were elucidated by comprehensive analysis of MS and NMR spectroscopic data. Their absolute configurations were deduced following the comparison of experimental and theoretically calculated ECD spectra and through biogenetic considerations. Goniomedine B (2) exhibited moderate activity against Plasmodium falciparum.

Synthesis and tubulin-binding properties of new allocolchicinoids

Allocolchicinoids with B- and C-ring variations were synthesized using sequential enyne-metathesis/ Diels-Alder reactions (A-->AB-->ABC approach) and evaluated for their inhibitory effect on tubulin assembly in vitro. (-)-Allocolchicine 11 with methyl ester at C10 and (+/-)-cyclopropyl allocolchicinoid 32 exhibit similar activity than (-)-colchicine (1), probably derived from a similar flexibility in the biphenyl system. The presence of methyl ester at C10 led to a little loss in potency in comparison with the series with methyl ester at C9. A complete loss of activity was observed for allocolchicine 9 with methyl ester at C11.

From Enantiopure Hydroxyaldehydes to Complex Heterocyclic Scaffolds: Development of Domino Petasis/Diels–Alder and Cross‐Metathesis/Michael Addition Reactions

One-step assembly of hexahydroisoindole scaffolds by a sequence that combines the Petasis (borono-Mannich) and Diels-Alder reactions is described. The unique selectivity observed experimentally was confirmed by quantum calculations. The current method is applicable to a broad range of substrates, including free sugars, and holds significant potential to efficiently and stereoselectively build new heterocyclic structures. This easy and fast entry to functionalized polycyclic compounds can be pursued by further transformations, for example, additional ring closure by a cross-metathesis/Michael addition domino sequence.

Facile synthesis of N-Boc-(2S,5R)-5-(1′-hydroxy-1′-methylethyl)proline

Abstract Coupling of chiral 1- O -benzylglycerol-2,3-bistriflate with trilithiated chiral 2- N -Boc-3-phenylsulfonylpropan-1-ol derivative constitutes an efficient route to chiral C-5 substituted prolines which can potentially induce cis Xaa-Pro peptide bond conformation. A straightforward seven-step synthesis of the title compound is described.

Symmetrically-substituted decalin-based scaffolds

Abstract The synthesis of a chiral scaffold was achieved by coupling a decalintriol platform with a NH-Boc protected α-ethylenic γ-amino acid. The two side chains of this molecule strongly self-associate through intramolecular hydrogen bonding involving the NH-Boc residues.