Involved in the synthesis of tocopherol (vitamin E). Catalyzes the condensation of homogentisate and phytyl diphosphate to form dimethylphytylhydrquinone (By similarity). H(+) + homogentisate + phytyl diphosphate = 2-methyl-6-phytyl-1,4-benzene-1,4-diol + CO2 + diphosphate Cofactor biosynthesis; tocopherol biosynthesis. Belongs to the UbiA prenyltransferase family.