Recently we reported a new method for the substitution of an hydroxy-or methoxy-group on the bridgehead carbon atom in the bicyclo[2.2.2]octane series by halogens (I), using various halogenating agents [e.g. POCl3, SOC12, PBr3 and also alkali chlorides, bromides or iodide8 (2)] in the presence of polyphosphoric acid (PPA). We wish now to describe a facile new synthesis of i.4dihydroxybicyclo(2.2.2loctane together with an extension of the halogenation 'reaction to the substitution of both hydroxy-or acetoxy-groups by halogens on bridgehead atoms, represented by the preparation of 1,4-dihalogenobicyclo[2.2.2]octanes. The acid-catalyzed reaction of isopropenyl acetate (IPA) with 1.4~cyclohexanedione [forming a mixture of 1,4-diacetoxycyclohexa-1,3-diene (I) and 1,4-diacetoxycyclohexa-1,4-diene (II)] in the presence of maleic anhydride (MA) resulted in trapping of I as the Diels-Alder adduct, 1,4-diacetoxy-' bicyclo(2.2.2]oct-5-ene-2,3-dicarboxylic anhydride (III) * in 50 -55 % yield, m.p. 2iO-2ii.5° (benzene). Hydrogenation with Adams catalyst at atmospheric pressure in tetrahydrofuran gave 1,4-diacetoxybicyclo[2.2.2]octane-2,3dicarboxylic acid anhydride (IV), m.p. lS4-lS5.5O (acetone), in 99 % yield, which upon hydrolysis in 20 % aqueous potassium hydrogen carbonate and subsequent acidification with hydrochloric acid resulted in 94 % yield of 1,4-diacetoxybicyclo[2.2.2]octane-2,3-dicarbaxylic acid (V), m-p. iG9.5-190° *I Satisfactory elemental analyses were obtained for all compounds and consistent infrared and n.m.r. spectra reported herein.