Biomimetic synthesis of nitraramine

Article abstract of DOI:10.1021/jo00122a052

The synthesis of a possible biosynthetic precursor (9) of nitraramine (1) is described, utilizing N-Boc-piperidone as an equivalent of didehydropiperidine 4. Heating this reactive, achiral intermediate 9 in aqueous solution results in the stereoselective formation of natural nitraramine via three successive cyclization reactions. Since nitraramine and several other Nitraria alkaloids are obtained from Nitraria species in racemic form, this synthesis provides additional support for our hypothesis of non-enzyme-catalyzed formation of these alkaloids.