Asymmetric total synthesis of (+)-2-epi-deoxoprosopinine

The asymmetric synthesis of (+)-2-epi-deoxoprosopinine [(S,S,R)-5] in eleve n steps and with excellent diastereomeric and enantiomeric purity (de, ee g reater than or equal to 96%) is described. As key steps, the 1,2-addition o f a dodecyl nucleophile to an aldehyde-SAMP hydrazone and the alpha -alkyla tion of 2,2-dimethyl-1,3-dioxan-5-one SAMP hydrazone are employed to genera te two of the three stereogenic centers. Creation of the third stereogenic center was achieved in a domino deprotection/cyclisation/reduction sequence .