Enantiospecific, diastereoselective synthesis of Aspidosperma alkaloid analogues from secologanin

Pure enantiomers of two diastereomeric Aspidosperma alkaloid analogues antipodal at the spiro and adjacent centres have been prepared, as kinetic and thermodynamic products, respectively, in a biomimetic sequence via a secodine-like intermediate from a secologanin derivative and Kuehneʹs indolo-azepine.