Reagent for the N-protection of amines, e.g. adenine in the presence of K2CO3 in DMF, as pivaloyloxymethyl (Pom) derivatives, which have been found useful in the synthesis of sensitive nucleosides. The Pom group is cleaved in mild base, e.g. methanolic ammonia: J. Am. Chem. Soc., 89, 5439 (1967).