Abstract: Cantharidin, exo-4a,7a-dimethyl-4,7-epoxyhexahydroisobenzofuran-l,3-dione (1),has displayed significant antitumer activities in vitro and in vivo. The adverse effects on urinary and gastrointestinal tracts prevent it to be accepted by the clinic. The structural modification of cantharidin was suggested by us with the aim to decrease its toxicity and maintain or increase its activity. Organophosphorous-containing molecules of pharmaceutical use, such as the α-aminophosphonic acid dipeptide, alaphosphin (2), which inhibits alanine racemase^[2],are becoming increasingly important. We therefore designed and synthesized a series of phosphonodipeptide derivatives with α-aminoalkylphosphonate in N-terminal of exo-(7-oxa)bicyclo[2.2.1]heptane(or exo-bicyclo[2.2.l]hept-5-ene)-2,3-dicarboxylic anhydride, which might be interesting to people researching in the areas of chemistry, biochemistry and pharmacology.