M. F. Renard

Reduction microbiologique d'aldehydes α, β-ethyleniques par Beauveria sulfurescens

Abstract αβ-unsaturated aldehydes are reduced by Beauveria sulfurescens , giving a mixture of the corresponding ethylenic and saturated alcohols. Optically active saturated alcohols have the ( S )-configuration.

Microbial reduction of α,β-unsaturated carbonyl compounds: A general property?

Abstract The double bonds of cyclohexenone and methylcyclohexenone were reduced by a strain of Clostridium and by various strains of Streptomyces . These results and those observed previously show that this reduction is widespread among microorganisms.

Generationof 1-seleno-allyl cations and the reactions with furan and pyrrole

Abstract 1,3-bis (seleno)-propenes are valuable precursors of selenium stabilized allyl cations which react with furan and N-methyl pyrrole in a highly stereoselective fashion to give electrophilic substitution products.

Metallation of 2-phenylindolizine

Abstract Regioselective metallation of 2-phenylindolizine at C(5) and subsequent reaction with an electrophile has afforded the corresponding C(5) functionalised indolizine in high yields.

Reduction of 1,1-dideuterio-2-methyl-2-penten-1-ol by beauveria sulfurescens. Mechanism of the microbiological reduction of α,β-unsaturated ald

Abstract Reduction of 1,1-dideuterio-2-methyl-2-penten-1-ol by Beauveria sulfurescens leads to the corresponding saturated mono-deuterated alcohol. This result allows the understanding of the mechanism of the microbiological reduction of α,β-unsaturated alcohols by B. sulfurescens. Thus, the stereochemical rule previously established for the reduction of α,β-unsaturated ketones can be carried out to the reduction of unsaturated aldehydes by B. sulfurescens.

Microbiological synthesis and circular dichroism of optically active 2-deuterio-cycloalkanones

Abstract Optically active 2-deuterio-cyclopentanone and 2-deuterio-cyclohexanone have been prepared by microbiological reduction of 2-deuterio α,β-unsaturated cyclic ketones by Beauveria sulfurescens .

Microbial Oxidation of Vinyl Sulfides to Chiral sulfoxides

A variety of bacteria, yeasts and fungi were screened for the preparation of enantiomers of chiral sulfoxides from aryl-aryl or alkyl-aryl (E) and (Z) vinyl sulfides 1. The asymmetric oxidation was studied on a model substrate, (E)-methyl-(2-phenyl)-vinylsulfide la. Along with various amounts of sulfone, all strains tested gave the corresponding sulfoxide, optically active, albeit with different chemical and optical yields. The stereochemical outcome of the reaction appears to be quite invariant and both enantiomers can be obtained. The high sensitivity towards substrate structure observed in a variety of sulfides is related to the toxicity of the substrates and the microbial oxidation is therefore assumed to be a detoxication reaction.

Multifunctional catalysis XI : Asymmetric catalysis of the mutarotation of tetramethylglucose by optically active phosphinothioic acids.

Abstract Catalytic activities of R(+) and racemic t-butylphenylphosphinothioic acids on the mutarotation of 2,3,4,6 tetramethyl-d-glucose are studied in benzene.

Isomerisation de la Δ5 cholestenone catalysee par quelques oxyacides phosphores

Abstract The isomerisation of Δ5 cholestenone catalysed by some oxyacids containing phosphorus has been studied. A reaction mechanism is outlined, which agrees with that already proposed using carboxylic acids, two molecules of the catalyst being involved. Phosphorous oxyacids are better catalysts than carboxylic acids. The kinetic law is complex because of the high polymerisation of these acids. The polymerisation constants are given for the first time.

Synthesis of meso-tetravinyl porphyrins through 1-selenoallyl cationic species

The highly regioselective reaction of postulated 1-methylseleno-allyl cations with pyrrole permits the one-pot synthesis of a series of novel prophyrins; alternatively, β-methylcrotonaldehyde gives (5a).