[EN] NOVEL SUBSTITUTED ARYLHEXADIENOIC ACIDS AND ESTERS THEREOF WHICH CAN BE USED FOR THE TREATMENT AND PREVENTION OF DIABETES, DYSLIPIDAEMIA AND ATHEROSCLEROSIS, PHARMACEUTICAL COMPOSITIONS COMPRISING THEM AND PROCESSES FOR THE PREPARATION OF THEM [FR] NOUVEAUX ACIDES ARYL-HEXADIENOIQUES SUBSTITUES ET LEURS ESTERS POUVANT ETRE UTILISES POUR LE TRAITEMENT ET LA PREVENTION DU DIABETE, DE LA DYSLIPIDEMIE ET DE L'ATHEROSCLEROSE, COMPOSITIONS PHARMACEUTIQUES LES CONTENANT ET PROCEDES DE PREPARATION