Chunfook Wong

PROPERTIES OF SULFUR CONTAINING NUPHAR ALKALOIDS

Abstract The various types of Nuphar alkaloids are noted and thereafter attention is focused on one of these types, the thiaspirane Nuphar alkaloids. A brief discussion of the spectral characteristics useful in ascertaining the gross structure is followed by a more detailed discussion of the spectral properties, primarily 1H and 13C NMR and the CD, and the chemistry employed to establish the stereochemistry of the thiaspiranes. Emphasis is given to sulfur atom-immonium ion interactions which are revealed in studies of metal hydride reduction and the UV and CD of α- and β-thiohemiaminals. Finally an indication of the biological activities of thiohemiaminal thiaspirane and synthetic analogs is presented.