PROCEDIMIENTO PARA LA SINTESIS DE LACTONAS DERIVADAS DEL ACIDO p-HIDROXIFENIL PROPIONICO

Process for the synthesis of lactones derived from p-hydroxyphenyl propionic acid, in the form of mixtures of cis/trans diastereomers of formula (I) or (ia), *** image-01 *** Where n can take values 1, 2 and 3; r can be h or ch3 and r1 can be h or ch3, which comprises: A) oxidation of the compound of formula (IV) or the corresponding one of the naphthyl series (iva) in the presence of oxalyl chloride and dimethyl sulfoxide in dichloromethane at -78ºC (swern oxidation) *** image-02 *** Where n can take values 1, 2 and 3; r can be h or ch3 B) treat the product derived from the previous step with the brominated derivative (II) in the presence of a metal and a solvent or mixture of solvents *** image-03 *** Where r1 can be h or ch3. (Machine-translation by Google Translate, not legally binding)