Abstract: A region-specific monofunctionalization of a phenolic hydroxy onto a polyphenol for the preparation of a compound of the formula ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl of 1 to 8 carbon atoms, alkenyl and alkynyl of 2 to 8 carbon atoms, --CN, formyl, carboxy, alkoxy carbonyl of up to 9 carbon atoms, aralkoxy carbonyl or up to 12 carbon atoms and halogen and R' is a hydroxy protective group comprising reacting a polyphenol of the formula ##STR2## wherein R has the above definition with a base to form the corresponding dianion, reacting the latter with a trialkyl borate of the formulaB(OAlk).sub.3wherein Alk is alkyl of 1 to 6 carbon atoms to form a compound of the formula ##STR3## reacting the latter with a reagent capable of introducing a hydroxy protective group and reacting the latter with a hydrolysis agent for the oxygen-boron bond to obtain the corresponding compound of Formula I.