A new kind of analogues of coenzyme B~1~2 base-off form, which are cobinamides containing 2'-deoxynucleosides, were synthesized by an improved method. They are 2',5'-dideoxyuridinylcobinamide, 2',5'- dideoxyadenosylcobinamide, 2',5'-dideoxycytidylcobinamide, and 5'- deoxythymidylcobinamide. All the four analogues were investigated by UV-Vis and 2D ^1H NMR spectroscopies. The spectroscopic properties with those of their corresponding cobalamins were compared.

Key words: ANALOGUE, SPECTRAL PROPERTIES, DEOXYRIBONUCLEOSIDE, COBINAMIDE