OCCURRENCE OF PHENYLPYRUVIC ACID IN WOODY-PLANTS - BIOSYNTHETIC SIGNIFICANCE AND SYNTHESIS OF AN ENOLIC GLUCOSIDE DERIVATIVE

The leaves and stems of Aspalathus linearis, a member of the Fabaceae, contains (Z)-2-(beta-D- glucopyranosyloxy)-3-phenylpropenoic acid 1, an enolic glucoside of phenylpyruvic acid, representing the first uneq uivocal evidence for the latter's presence in woody plants. The synthe sis of a derivative 2 of the natural product, and of related regiomeri c and geometrical isomers 3, 4 and 5, and the biosynthetic significanc e in relation to the shikimic acid pathway are discussed.