We describe an integrated set of experiments for the undergraduate organic laboratory that allows students to compare and contrast biological and chemical means of introducing chirality into a molecule. The racemic reduction of ethyl acetoacetate with sodium borohydride and the same reduction in the presence of a tartaric acid ligand are described, and a capillary gas chromatography column packed with a chiral material for product analysis is introduced. The results of these two hydride reactions are compared with the results of a common undergraduate experiment, the baker's yeast reduction of ethyl acetoacetate.

The reaction of a-lactams with alkynyl-lithium reagents affords 2-pyrrolin-4-ones and constitutes a useful synthesis of this class of heterocycles bearing bulky aliphatic substituents.

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Die Umsetzung der Aziridinone (I) mit dem metallierten Dithianderivat (II) liefert unter Spaltung der Acyl‐Stickstoff‐Bindung die Aminoketone (III).

Aus den α‐Lactamen (I) und dem Lithiumacetylid (II) erhält man unter Ringspaltung die Verbindungen (III), deren Cyclisierung zu den Pyrrolinonen (IV) führt.