An enantioselective two-step route to substituted benzo[
a]- and indolo[2,3-
a]quinolizidines has beendeveloped. It consists of (i) a stereoselective cyclocondensation of a racemic or prochiral
![](/images/gifchars/delta.gif)
-oxo(di)esterwith either (
S)-(3,4-dimethoxyphenyl)alaninol or (
S)-tryptophanol in a process involving a dynamic kineticresolution and/or the differentiation of enantiotopic or diastereotopic ester groups, and (ii) a subsequentstereocontrolled cyclization on the aromatic ring taking advantage of the masked
N-acyl iminium ionpresent in the resulting oxazolopiperidone lactams.