Remarkable stereoselectivity in intramolecular Borono-Mannich reactions: synthesis of conduramines.
Résumé
An unprecedented intramolecular Petasis condensation provides a novel approach to biologically important conduramines. The compounds are produced with an exclusive anti stereoselectivity for the newly created β-amino alcohol motif. The stereochemical outcome of the reaction is opposite to the one usually observed in the intermolecular reaction.