2-deoxy-L-erythro-pentopyranose-tris(4-methylbenzoate) is an intermediate in the synthesis of 2-Deoxy-D-α-ribopyranosyl-5-azacytosine which is an isomer of 2-Deoxy-D-β-ribopyranosyl-5-azacytosine (D253525), an impurity of Decitabine and potentially carcinogenic.