Oxygen-substituted phenylacetic acids have been employed in the synthesis of a wide variety of natural products, embracing such diverse species as flavonoids and alkaloids.'p2 One especially important area is their use in the synthesis of the opiate alkaloid^.^^^ Rice has employed (3-hydroxy-4-methoxypheny1) acetic acid (1, homoisovanillic acid) in a concise synthesis of the opiate precursor dihydrothebainone.% d In a related approach to ...
