The condensation of 2,5,6-trimethyl-3-(4-iodobutyl)hydroquinone (I) with octa-2,7-diyn-1-ol tetrahydropyranyl ether (II) by means of sodium amide in liquid ammonia gives 2,5,6-trimethyl-3-[12-(tetrahydropyranyloxy)-5,10-dodecadiynyl]hydroquinone (III), which is oxidized with ceric ammonium nitrate in aqueous acetonitrile and deprotected in the usual way.