AbstractThe mass spectral behaviour of tetraacetyl spermine (2) has been investigated. The fragmentation reactions are characterized by the neighbouring group participation of the amide nitrogen atoms. Only a few reactions can be explained by usual pathways (α‐cleavage, onium reactions). Most of the fragment‐ions are formed by neighbouring group participation:1[M‐COCH3]+‐Ion.2Breakdown of one of the two 1,3‐diaminopropan moieties:m/e242, 256, 268. This type of fragmentation is characteristic for all acetylated 1,3‐diaminopropan‐derivatives e.g. triacetylspermidine.3Expulsion of a neutral amine:m/e169.4SNi‐type reactions, by which cyclic ions a