The present invention provides a scalable synthesis of enantiomerically pure brivaracetam, and related derivatives.

The present invention provides a scalable synthesis of enantiomerically pure brivaracetam, and related derivatives.

The process for producing polyhydroxyalkanoates or PHA from volatile fatty acid (VFA) molecules, referred to as precursors, produced by anaerobic fermentation from fermentable biomass, characterized in that it comprises at least the following steps: a) extracting the volatile fatty acid (VFA) molecules, without stopping the fermentation, via an extraction means chosen from means that are, at least, insoluble in the fermentation medium, b) collecting, outside the fermentation reactor, the volatile fatty acid (VFA) molecules once they have been extracted, c) synthesizing, by halogenation, using a type of volatile fatty acid (VFA) chosen from the volatile fatty acids collected in step b) and defined according to the desired type of PHA, a given -halo acid, d) synthesizing from this -halo acid molecules of a given -hydroxy acid by reaction with a base, e) polymerizing using the -hydroxy acid obtained a defined polyhydroxyalkanoate (PHA).

The process for producing polyhydroxyalkanoates or PHA from volatile fatty acid (VFA) molecules, referred to as precursors, produced by anaerobic fermentation from fermentable biomass, characterized in that it comprises at least the following steps: a) extracting the volatile fatty acid (VFA) molecules, without stopping the fermentation, via an extraction means chosen from means that are, at least, insoluble in the fermentation medium, b) collecting, outside the fermentation reactor, the volatile fatty acid (VFA) molecules once they have been extracted, c) synthesizing, by halogenation, using a type of volatile fatty acid (VFA) chosen from the volatile fatty acids collected in step b) and defined according to the desired type of PHA, a given -halo acid, d) synthesizing from this -halo acid molecules of a given -hydroxy acid by reaction with a base, e) polymerizing using the -hydroxy acid obtained a defined polyhydroxyalkanoate (PHA).

Provided is a production method whereby corresponding carboxylic acid anhydrides and carboxylic acid esters can be obtained at high yield from various carboxylic acids even without a solvent and near room temperature. A method for producing a carboxylic acid anhydride represented by formula (II), the method comprising reacting a compound represented by formula (I) and a carboxylic acid in the presence of a Group II metal compound having an ionic ligand containing an oxygen atom. A method for producing a carboxylic acid ester, the method comprising reacting a carboxylic acid anhydride produced by the aforementioned method and an alcohol. In formula (I), R.sup.1 represents a C.sub.1-20 hydrocarbon group. In formula (II), R.sup.2 represents a C.sub.1-20 hydrocarbon group.

Provided is a production method whereby corresponding carboxylic acid anhydrides and carboxylic acid esters can be obtained at high yield from various carboxylic acids even without a solvent and near room temperature. A method for producing a carboxylic acid anhydride represented by formula (II), the method comprising reacting a compound represented by formula (I) and a carboxylic acid in the presence of a Group II metal compound having an ionic ligand containing an oxygen atom. A method for producing a carboxylic acid ester, the method comprising reacting a carboxylic acid anhydride produced by the aforementioned method and an alcohol. In formula (I), R.sup.1 represents a C.sub.1-20 hydrocarbon group. In formula (II), R.sup.2 represents a C.sub.1-20 hydrocarbon group.