Diastereoselective synthesis of cis-3- and 3,5-alkylpyrrolizidines

Cis‐3 and 3,5‐substituted pyrrolizidines can be prepared from β‐enaminolactones. Substituted pyrrolidinoketones lead to these compounds by an amino reductive annelation with a low diastereomeric excess, but a best access to these azabicycles consists in preparing cis‐2,5‐disubstituted pyrrolidines which are then transformed into the expected heterocycles.