The ring-expansion reactions of heterocyclic ketoximes and carbocyclic ketoximes with several reductants such as AlHCl₂, AlH₃ (alane), LiAlH₄, LiAlH(O^tBu)₃, and (MeOCH₂CH₂O)₂AlH₂Na (Red-Al) were examined. Among reductants, AlHCl₂ (LiAlH₄:AlCl₃ = 1:3) in cyclopentyl methyl ether (CPME) has been found to be a suitable reagent for the reaction, and the rearranged cyclic secondary amines were obtained in good to excellent yields.

Synthetic studies on a 17β-hydroxysteroid dehydrogenase type 3 (17β-HSD3) inhibitor are described. The unsymmetrical dibenzazocine skeleton was constructed by a regiocontrolled ring-expansion reaction of a cyclic oxime with DIBAL-H.