The condensation of nitromethane (I) with formaldehyde (II) by means of NaOH in water gives 2-nitropropane-1,3-diol (III), which is brominated with Br2 in ethyl acetate yielding 2-bromo-2-nitropropane-1,3-diol (IV) (1). Finally this compound is condensed with acetaldehyde (V) by means of p-toluenesulfonic acid in refluxing benzene (1-3).