Christine Gravier-Pelletier

Synthesis of (-)-Muricatacin and (-)-(5R,6S)-6-acetoxy-5-hexadecanolide, the Mosquito oviposition attractant pheromone, from D-isoascorbic acid

Abstract From D -isoascorbic acid, a general approach to enantiomerically pure hydroxy γ-butyro and δ-valero lactones, (-)-Muricatacin and (-)-(5 R ,6 S )-6-acetoxy-5-hexadecanolide, via a four carbon atoms bis-epoxide equivalent, is reported.

Liposidomycins − Synthetic Studies Towards the Ribosyldiazepanone Moiety

A synthesis of the enantiopure 2-ribosyl-1,4-diazepan-3-one core of liposidomycins, a class of complex lipid nucleoside antibiotics, according to a flexible asymmetric synthesis strategy is described. It involves two building blocks, an enantiopure α-azido-β,γ-epoxybutanol readily available from L-ascorbic acid, and an α-ribosylamino acid obtained from D-ribose. Subsequent cyclization by regiospecific nucleophilic opening of the epoxide by the amino acid followed by peptidic coupling affords the target ribosyl diazepanone.

ACCESS TO ENANTIOPURE RIBOSYL-DIAZEPANONE CORE OF LIPOSIDOMYCINS

Abstract A convergent synthesis of the ribosyl-diazepanone core of liposidomycins, new nucleoside antibiotics, has been carried out via enantiomerically pure epoxide and α-ribosyl aminoacid, chiral key intermediates obtained from L-ascorbic acid and D-ribose, respectively.

A General Way, From L-Ascorbic And D-Isoascorbic Acids, To Homochiral α-Hydroxy, α,β-Dihydroxy And α,β-Epoxy-Aldehydes, Useful Building Blocks For The Synthesis Of Linear Oxygenated Fatty Acids Metabolites

AbstractEnantiomerically pure α-hydroxy, α,β-dihydroxy and α,β-epoxyaldehydes, useful building blocks for the synthesis of acyclic oxygenated fatty acids metabolites, were synthetized via epoxybutanediol acetonide starting from the commercially available L-ascorbic and D-isoascorbic acids.

Chiral α-hydroxy- and α,β-dihydroxy- aldehydes from D-isoascorbic and L-ascorbic acids. Useful precursors for the synthesis of fatty acid metabolites.

Abstract The four possible stereoisomers of α,β-dihydroxyaldehydes, useful building blocks for the synthesis of fatty acids metabolites, are synthesized via epoxy-tetrols derived from D-isoascorbic and L-ascorbic acids. The general method we develop allows the synthesis of chiral α-hydroxyaldehydes as well.

Efficient route to optically pure polyfunctionalized cyclooctanes

Abstract A short and efficient synthesis of enantiopure highly functionalized eight-membered carbocyclic rings is described from 1,2:5,6-bis-epoxides issued from d -mannitol. The key cyclization step involves the metathesis of 1,9-diene using Grubbs’ catalyst or the pinacolic coupling of 1,8-dialdehyde resulting from the oxidative cleavage of the previous diene. In the specific case of ring-closing metathesis cyclization, the influence of a conformationally restricted diene compared to that of a flexible one has been evaluated.

Enantiopure hydroxylactones from L-ascorbic and D-isoascorbic acids. Part II. Synthesis of (−)-(5R, 6S)-6-acetoxy-5-hexadecanolide and its diastereomers☆

Abstract Strategies to enantiopure 6-hydroxy-δ-valerolactones, through bis-epoxide formal equivalents issued from L-ascorbic and D-isoascorbic acids, are studied. The approaches notably involve Mitsunobu reaction on diols or triols and opening of the resulting epoxides.

Efficient access to azadisaccharide analogues

Abstract The synthesis of various aminocyclitols as pseudo-azadisaccharide candidates for glycosidase inhibition is described. The strategy involves the reductive amination with several amines of polyhydroxycycloheptanones resulting from a tandem alkylation–cyclisation of C 2 -symmetrical bis-epoxides derived from d -mannitol.

On the Way to Liposidomycins, New Nucleoside Antibiotics. Access to the Homochiral Diazepanone Core

Abstract Access to the homochiral diazepanone core of liposidomycins has been carried out through the regiospecific nucleophilic opening of an enantiomerically pure α-amino-β,γ-epoxy-acid precursor, by an L-amino acid derivative, on one hand and cyclisation by a peptidic coupling reaction, on the other hand.

Bacterial transferase MraY inhibitors: Synthesis and biological evaluation

New inhibitors of the bacterial transferase MraY are described. Their structure is based on an aminoribosyl-O-uridine like scaffold, readily obtained in two key steps. The amino group can be coupled with proline or guanylated. Alternatively, these amino, prolinyl or guanidinyl groups can be introduced through a triazole linker. Biological evaluation of these compounds on MraY from Bacillus subtilis revealed interesting inhibitory activity for both amino compounds.