Synthetic applications of 2-aryl-4-piperidones. XI a new synthesis of the E-azaeburnamine skeleton

Article abstract of DOI:10.1016/0040-4020(96)00399-7

17-Azaeburnamine type compound 2 is synthesized by closure of ring E on 1-aminoindolo[2,3-a]quinolizidine 8. Compound 8 is obtained by a Neber rearrangement on the corresponding indolo[2,3- a]quinolizidin-2-one, or by K(t)BuO cyclisation of 3-amino-2-(2- indolyl)piperidin-4-one 16. In both cases the starting substrate is 4-piperidone 3. The synthesis of the new [ABED] ring system 6 is also described.