Unexpected rearrangement of enantiomerically pure 3‐aminoquinuclidine as a simple way of preparing diastereomeric octahydropyrrolo[2,3‐c]pyridine derivatives

Reaction of ( S )‐ or ( R )‐3‐aminoquinuclidine with 2‐chloropyrimidine or 2‐bromopyrimidine led to an unexpected formation of both cis ‐ and trans ‐octahydropyrrolo [2,3]pyridine derivatives. A single‐step synthesis of two of the four stereoisomers of these octahydropyrrolo[2,3]pyridine derivatives provides a convenient way of generating stereochemically defined isomers. Optimization of reaction conditions was carried out by 1 H NMR monitoring. The relative and absolute stereochemistry of all four stereoisomers was determined by a combination of 1 H, 13 C, and 15 N NMR spectroscopy and vibrational circular dichroism spectroscopy. Chirality, 2009. © 2008 Wiley‐Liss, Inc.