Ozone as a Ketal Deprotective Agent

Schimmel/Conrades Science Center Atrium

Because of ozone’s distinct oxidation strength, reactions with ozone is limited to the destruction of structure in non-stereospecific patterns, as commonly observed in the ozonolysis of alkenes and alkines. This project examined the use of ozone in the deprotection of cyclic ketals. Three cyclic ketals were synthesized from 4-phenylcyclohexan-1-one, and the deprotection of 8-phenyl-1,4-dioxaspiro[4.5]decane was examined in detail, using a combination of nuclear magnetic resonance (NMR) spectroscopy and gas chromatography/mass spectrometry (GC/MS). The desired deprotection proceeded in 25% yield, but was accompanied by the formation of several byproducts. A GC/MS method was developed that enabled the separation of these byproducts, and work to establish their identity is ongoing.