A general synthetic route to the acarnidines (1) is described. The acarnidines (1) were isolated from the marine sponge Acarnus erithacus and were reported to possess antimicrobial activity and modest antiviral activity. Twenty-one acarnidines and analogues have been prepared so that structure-activity comparisons could be made. Although there are several reported methods for assembling acyclic triamines and amidoalkylguanidines the synthesis of derivatives in this work has been restricted by a lack of sensitivity, forcing conditions or because bis-products were formed. To overcome these problems a convergent synthetic strategy has been developed which made use of monoprotected diamines. Reductive alkylation of the aminesled to acyl triamines which could be further selectively acylated and amidinated to form the acarnidines. Many other synthetic methods that were attempted, but failed, are also described.