Patent ID: 7928254

Claim:
A method for preparing a compound of the following formula (I): wherein: R 3 represents H or a linear or branched R 4 alkyl group comprising 1 to 6 carbon atoms, R 1 represents: H, F, CI, Br, CF 3 or a linear or branched alkyl group comprising from 1 to 6 carbon atoms, said alkyl group being optionally substituted with a halogen atom; and n is greater than 4, said preparation method comprising: the application of the Wittig-Horner reaction by reacting a phosphonate of the following formula (III): wherein: R 1 is as defined above, R 2 represents a linear or branched alkyl group, comprising from 1 to 6 carbon atoms , said R 2 groups may form a cyclic group with the oxygen atoms of the OR 2 groups and the phosphorus atom of the P═O group, and R 4 represents a linear or branched alkyl group, comprising from 1 to 6 carbon atoms, or, when R 1 ═H, the application of the Doebner-Knoevenagel reaction by reacting a malonic acid derivative of formula R 3 OOC—CH 2 —COOR 3 , R 3 being as defined above, on a lactol of the following formula (II): n being as defined above, in order to obtain a hydroxyester of the following formula (IV): wherein n, R 3 and R 1 are as defined above, and optionally, when R 3 represents a group R 4 as defined above, a reaction for saponifying the hydroxyester of the aforementioned formula (IV) in order to obtain a hydroxyacid of the following formula (I): wherein n and R 1 are as defined above.