Abstract:
The monoconjugates of phenolic acids (i.e. coumaric acid) with polyamines
such as spermidine and spermine are strikingly similar to some toxins from
spiders and predatory wasps. Many plants contain phenolic acid polyamine
conjugates and there is some reliable information supporting their roles as
plant defense chemicals. Eleven monoacylated compounds of diamines,
triamines, tetraamines and oxa-polyamine amines were prepared in three to
seven steps: 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 and 32. The synthesis
proceeds through stepwise construction of the polyamine backbone (as in 62
and 72), followed by protection and deprotection steps of the amino
functions. Desymmetrization of readily available and prepared symmetrical
polyamines is a key step in the synthesis. The protecting groups employed
were tert-butoxycarbonyl (BOC) and trifluoroacetyl (TFA) group which
were removed under different conditions: acid and base respectively.
Deprotection and refunctionalization of the polyamine reagent demonstrated
the versatility of these systems for N-acylation.
