Synthetic Studies of Zoanthamine/Norzoanthamine. Biogenetic-like One-Step Construction of the Heterocyclic Aminal Core (CDEFG Ring) from a Monocyclic Precursor.
Biogenetic-like one-step construction of the pentacyclic aminal core of zoanthamine/norzoanthamine alkaloids was accomplished in high yield from the suitably protected monocyclic aminohydroxy diketocarboxylic acid 7 by heating in aqueous acetic acid.