Oxygen Bonded to Trigonal Carbon Atoms

It was found that acidic or basic properties of metal oxides are not directly connected to their hydrogenolytic power, but redox properties seem to play a more important role.19 

It is possible that the Sn atoms participate by complexation but there is no direct evidence in favor of this hypothesis.22 

Lactones can be hydrogenolyzed on copper chromite catalysts.23 Diol formation is favored at lower temperatures, whereas higher temperatures give cyclic ethers. This process is not widely used, however, because of experimental difficulties. 

It has been found that furans undergo hydrogenolyses under very mild conditions. Such conditions are too mild to hydrogenolyze oxolanes (saturated furans). As concerns regioselectivity, the furan C-O bond rupture takes place in the sterically less hindered position, similar to the reaction in the oxolanes. The oxacycloalkene intermediate of an intramolecular Diels-Alder furan reaction was hydrogenolized over Pd/BaS04.27 

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