Method for producing cis-4-aminotetrahyrdrofuran-2-carboxylic acid esters

A process for preparing compounds of general formula (I) or salts thereof

• in which
• R1 is (C1-C6) alkyl or (C3-C6) cycloalkyl,
• characterized in that in a first reaction step compounds of general formula (II)
• in which
• R1 is as defined above,
• react with an amine of general formula (III) or salts thereof
• in which
• R2 is H, (C1-C4) alkyl, or an unsubstituted or substituted phenyl,
• R3 is H, halogen, (C1-C4) alkyl or (C1-C4) alkoxy,
• in the presence of H2 and a catalyst in a solvent to form compounds of general formula (IV) or salts thereof
• where R1, R2 and R3 are as defined above,
• and said compounds are then converted in a second reaction step in the presence of H2 and a catalyst in a solvent into compounds of the general formula (I) or salts thereof.