Previous syntheses of Z-[p-(2-methyl-2-hydroxy-propyl) phenyl] propionic acid (1), lt2 a major human metabolite of ibuprofen (II), were considered unsuitable for preparation of large quantities of pure I which were required for analytical studies. We report here a short, efficient synthesis of 2-[p-(2-methyl-2-hydroxypropyl)-phenyl] propionic acid, I, from ibuprofen, employing a novel 1, 6-eliminative cleavage of an epoxide which may have ...