The synthesis of 1 may be effected by condensation of 3, 4-[2-(2-carboxy-ethyl)-3-(6-E-hexyl)-phenoxy]-butyric, protected as a di-ester for Ro = lower alkyl, preferably as a di-ethyl ester (Ro = ethyl), and E is a leaving group, such as a halogen or mesylate with the fragment 2 wherein D is a nucleophile such as a hydroxyl group under standard conditions employed for the alkylation of phenols with