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Ketones were found to catalyze the decomposition of peroxynitrite.

The synthesis of a series of novel C2 symmetrical chiral ketones and their activities in catalytic asymmetric epoxidations are described. The first cyclic ketone obtained from the process acted as the ideal template for the introduction of chiral elements. Results also showed that the ester groups that provide rigid and C2 symmetric structures to the cyclic ketones significantly influence the effectiveness of asymmetric epoxidations.

Experiments were performed to investigate the formation of a novel 1.8 (sub 8) helix or a twisted 2 (sub 8) helix with two residues per helical turn independent of side chains by homochiral oligomers of alpha-aminoxy acids. Chiral diamides were utilized to analyze the effects of side chains on the nitrogen-oxygen turn structure. H nuclear magnetic resonance studies were also performed. The findings indicate the significance of chiral alpha-aminoxy acids in the construction of combinatorial libraries.

The selective oxidation of unactivated carbon-hydrogen bonds (C-H) at the sigma site of ketones was examined using dioxiranes, an oxidant with excellent reactivity toward unactivated C-H bonds under moderate and neutral conditions. Two transition states (TS) in the concerted C-H bond oxidation by dioxiranes have been identified, the planar TS and the spiro TS. Results suggested that the intramolecular C-H bond oxidation by dioxiranes was highly regioselective and required a spiro transition state.

The use of chiral ketone catalysts with C2 symmetry enables the asymmetric epoxidation of trans-stilbenes with high enantioselectivity. However, the increase in enantioselectivity reaches a plateau and subsequently drops with increasing size of the steric sensor. Such catalysts, however, may also be used as probes to show that dioxirane epoxidation proceeds as a spiro transition state.

We found that dioxiranes generated in situ from ketones 1-6 and Oxone underwent intramolecular oxidation of unactivated C-H bonds at delta sites of ketones to yield tetrahydropyrans. From the trans/cis ratio of oxidation products 1a and 2a as well as the retention of the configuration at the delta site of ketone 5, we proposed that the oxidation reaction proceeds through a concerted pathway under a spiro transition state. The intramolecular oxidation of ketone 6 showed the preference for a tertiary delta C-H bond over a secondary one. This intramolecular oxidation method can be extended to the oxidation of the tertiary gamma' C-H bond of ketones 9 and 10. For ketone 11 with two delta C-H bonds and one gamma' C-H bond linked respectively by a sp(3) hydrocarbon tether and a sp(2) ester tether, the oxidation took place exclusively at the delta C-H bonds. Finally, by introducing proper tethers, regioselective hydroxylation of steroid ketones 12-14 have been achieved at the C-17, C-16, C-3, and C-5 positions.