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 formula B(OAlk).sub.3 wherein 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.
将
酚羟基区域特异性单官能团化到多
酚上,以制备式为##STR1##的化合物,其中R选自氢、1至8个碳原子的烷基、2至8个碳原子的烯基和炔基、--CN、甲酰、羧基、最多9个碳原子的烷氧羰基、最多12个碳原子的芳基烷氧羰基和卤素的羟基保护基,包括将式为##STR2##的多
酚(其中R具有上述定义)与碱反应以形成相应的二阴离子,将后者与式为B(OAlk).sub.3的三烷基
硼酸酯反应,其中Alk为1至6个碳原子的烷基,以形成式为##STR3##的化合物,将后者与能够引入羟基保护基的试剂反应,并将后者与氧
硼键的
水解剂反应,以获得相应的I式化合物。