The reaction between 1-aminosugars and trimethylisocyanate (TMSNCO) was optimised as a one-step synthetic strategy for the synthesis of sugar biurets. This protocol was successfully applied to a number of 1-aminosugars, which exclusively provided the corresponding biurets in 67-99% yields. The new methodology was applied in the de novo synthesis of N1-(2-deoxy-α/β-d-erythro-pentofuranosyl)biuret (dfBU) and N1-(2-deoxy-α/β-d-erythro-pentopyranosyl)biuret (dpBU), two known DNA lesions arising from the hydroxyl radical induced decomposition of 2'-deoxycytidine (dCyd).