Synthesis of an aspidosperma alkaloid precursor: synthesis of (+)-aspidospermidine

The aspidosperma alkaloid precursor (-)-(4aR,8aS,8R)-4a-ethyl-decahydroquinolin-7-one 7 (hydrolilolidone) was prepared from (+)-(1'S,4aR, 8aS)- 4a-ethyl-1-(1'-phenylethyl)octahydroquinolin-7-one 3. In addition, a synthesis of (+)- aspidospermidine 9 using compound 7 as starting material is described.