Novel Ring Systems in Morphinoides II [1]: C8,17-Ethano-Bridged 4,5-Epoxyhasubanans

Summary.

 Claisen-Eschenmoser rearrangement of the 9,10-saturated derivative of 4,5-epoxyhasubanan-6β-ol affords the 8β-substituted amide which can be converted to the polycyclic quaternary ammonium salt 7 with an indolizidine substructure. An N-demethylation step with triethylborohydride leads to three products in accordance with the different possible positions of attack of the hydride ion to the strained ring system.