Facile, Stereocontrolled Synthetic Route towards Bis-functionalised Pyrrolizidines.

A simple and convenient method for the synthesis of bisfunctionalised pyrrolizidines starting from readily available N-Cbz-L-prolinal is described. This aldehyde was converted within two concise steps to the corresponding aminoepoxides, which were separately subjected to regioselective cyclisation induced by a reductive cleavage of the Cbz protecting group. The versatile and concise strategy holds great potential for practical application in the straightforward preparation of pyrrolizidine-based drugs and natural products. [ABSTRACT FROM AUTHOR]