This compound can be obtained in two different ways: 1) By condensation of 1-beta-D-arabinofuranosylcytosine (I) with docosanoyl anhydride (II) in hot dioxane. 2) By acylation of cytidine (III) with docosanoyl anhydride (II) as before to give N4-docosanoylcytidine (IV), which is then isomerized by treatment with POCl3 in ethyl acetate.