Interrupted Dance of Five Heteroatoms: Reinventing Ozonolysis to Make Geminal Alkoxyhydroperoxides from C═N Bonds.

Four heteroatoms dance in the cascade of four pericyclic reactions initiated by ozonolysis of C═N bonds. Switching from imines to semicarbazones introduces the fifth heteroatom that slows this dance, delays reaching the thermodynamically favorable escape path, and allows efficient interception of carbonyl oxides (Criegee intermediates, CIs) by an external nucleophile. The new three-component reaction of alcohols, ozone, and oximes/semicarbazones greatly facilitates synthetic access to monoperoxyacetals (alkoxyhydroperoxides).

The Ozone and Hydroperoxide Teamwork: Synthesis of Unsymmetrical Geminal Bisperoxides from Alkenes.

Alkene ozonolysis is mostly known as a textbook reaction, resulting in carbonyl compounds. The combination of ozone and hydroperoxide was found to lead to the construction of more oxygen-rich compounds, unsymmetrical geminal bisperoxides, avoiding as well further oxidation with ozone, hydroperoxide, and oxygen as peroxide rearrangements. The discovered three-component synthesis provided alkylperoxy hydroperoxides in 41-63% yield from alkenes.