Control of the regiospecific synthesis of dialkylpyrrolizidinones and their stereochemical behaviour using gas chromatography/mass spectrometry with chemical ionization

Abstract Pyrrolizidine alkaloids were synthesized via the cyclization of an epoxide prepared from a lactam. The regiospecific control of this reaction is demonstrated using gas chromatography/mass spectrometry. Ammonia chemical ionization mass spectrometry permits the determination of the cis–trans stereochemistry of the final products.