Process for the preparation of indanones

A process of making a compound of formula (I)

• comprising the steps of:
• a) addition of an amino compound H2NR to a compound of formula (II)
• followed by cyclization to a compound of formula (III);
• wherein the wavy bond in formula (II) indicates an unspecified configuration of the adjacent double bond;
• and
• the amino compound H2NR is selected from the group consisting of alkylamides, sulfonamides and carbamates;
• b) isomerization of compound of formula (III) to a compound of formula (IV);
• c) hydrolysis of compound of formula (IV) to compound of formula (I);
• wherein, in the compounds of formula (I), (II), (III) and/or (IV),
• R1 represents methyl, ethyl, ethenyl, a linear, branched or cyclic C3-10 alkyl or alkenyl group, or a phenyl group, optionally substituted;
• and
• R2, R3, R4, R5 and R6 each independently represent a hydrogen atom, methyl, ethyl, ethenyl, methoxy, ethoxy, ethenoxy, a linear, branched or cyclic C3-10 alkyl, alkenyl or alkoxy group, a halogen atom or a phenyl group, optionally substituted, and wherein the process is carried out in a one-pot procedure.