Starting from putrescine and the requisite carboxylic acids, first syntheses of bioactive
natural products gigantamide A, dasyclamide, and cucullamide were accomplished in
very good overall yields using an appropriate sequence of dehydrative coupling reactions.
The syntheses of the corresponding dehomo analogues of these natural products are
also described. Regioselective diisobutylaluminum hydride reduction of an unhindered
carbonyl group in citraconimide is the key step.
Key words
diamines - dehydrative coupling reactions - regioselective reduction - natural and
unnatural bisamides - synthesis