General methods of alkaloid synthesis. A new approach to functionalized hydrolulolidone Aspidosperma alkaloid precursors. A formal synthesis of (±)-aspidospermine
Abstract
A new method for the synthesis of an established hydrolulolidone Aspidosperma alkaloid precursor, (4), is presented which involves the acid-catalysed thermal rearrangement of a cyclopropyl-imine (10) to a 2-pyrroline (11) as a key stage.