Aspidosperma pentacyclic alkaloids belong to a class of biologically active compounds among which the antimitotic dimeric alkaloids are of particular interest. Many strategies have been devoted to their synthesis but none has previously invoked as intermediates hexahydrocarbazol-4-ones which possess the A, B and C rings of these alkaloids. The precursors of these functionalized synthons were arylenaminones 23, obtained in three steps from available starting materials N-benzylaniline and cyclohexane-1,3-dione. Photocyclization of substituted or unsubstituted arylenaminones 23 led in high yield to 4a-trans-hexahydrocarbazol-4-ones 1a and 1b. Angular alkylation of 1a gave stereospecifically cis- hexahydrocarbazol-4-ones 25. Starting from 1a the pentacyclic framework of Aspidosperma alkaloids has been elaborated and the total syntheses of (±)-N_a-benzylaspidospermidine 44, (±)-19-oxoaspidospermidine 39 and (±)- 19-oxoaspidofractinine 36 have been achieved in good yields.