Graphite Oxide Catalyzed Tetrahydropyranylation/Depyranylation Of Alcohols And Phenols As Well As Dehydration Of Alcohos

Graphite oxide (or graphene oxide) is an amorphous, non-stoichiometry, lowlytoxic, hygroscopic and weakly acidic organic polymer material. Variousoxygen-containing functional groups, such as epoxys, hydroxyls, carbonyls andcarboxyls, are located on the basal planes and the edges of the graphite platelets. Asfor its unique structure and property, graphite oxide has promising applications insolar cell, biosensing, catalysis and has attracted great attention of chemicalresearchers.In this paper, graphite oxide was used in tetrahydropyranyl protection anddeprotection of alcohols and phenols for the first time. Various alcohols and phenols,including the unsaturated ones, were steadily tetrahydropyranylated andsubsequently depyranylated into the corresponding products at room temperatureduring short reaction time in good to quantitative yields. Graphite oxide could bereused at least four times. This method is convenient, safe, economical andenvironmentally benign. Besides, this paper proposed reasonable mechnisams oftetrahydropyranylation and depyranylation catalyzed by GO. Graphite oxide wasprepared by an improved Hummers method and was identified with IR, Raman,XRD, XPS, elemental analysis and so on.At the same time, graphite oxide was used as the catalyst for dehydrating ofalcohols. Tertiary and secondary alcohols were converted to the correspondingalkenes. Primary alcohols and diols were converted to the corresponding ethers andcycloethers under moderate conditions. Graphite oxide showed highly catalyticactivity and good selectivity. As an efficient catalyst, it is easily available and cheap.