ω-Formylalkylphosphonates by acid hydrolysis of the corresponding acetals obtained from triethylphosphite and bromoacetals has been described. In aqueous solution in the presence of cyanide and amines these compounds give aminonitriles (Strecker) or hydantoins (Bucherer). These reactions give access to a large variety of compounds which by acid hydrolysis (Strecker) or basic then acid hydrolysis (Bucherer)