(Z)-2,2',4,4'-Tetramethoxystilbene-5,5'-diol and Its Oxidation

Abstract

In an attempt to isolate a phenanthrene-4,5-quinone the title stilbenediol (24) was prepared by a Wittig reaction. Deisopropylation of a (Z)- diisopropyloxystilbene with boron trichloride resulted in isomerization to the (E) diol (15), but the required (Z) diol (24) was prepared successfully from acetoxy -substituted intermediates, which were hydrolysed during the course of the reaction. Chemical or photochemical oxidation failed to give the desired phenanthrene - 4,5-quinone. A phenanthrenediquinone was obtained by oxidation of the (Z)-stilbenediol (24) with I,I-diacetoxyiodobenzene.