MMT, Npeoc-protected spermine, a valuable synthon for the solid phase synthesis of oligonucleotide oligospermine conjugates via guanidine linkers.

Solid phase spermine oligomerization via guanidine linkers was achieved using activated thiourea coupling reaction with primary amino group. Disymmetric spermine synthon was efficiently synthesised in eight steps from spermine. MMT group was used as coupling monitor and resulting oligomeric spermines were conjugated to oligonucleotides.