We have developed an efficient method for selective monobenzoylation of 1,2- and 1,3-diols in water catalyzed by Me(2)SnCl(2). Treatment of 1,2- and 1,3-diols with benzoyl chlorides, DMT-MM, and potassium carbonate in the presence of a catalytic amount of Me(2)SnCl(2) and DMAP in water at room temperature gave monobenzoates in up to 97% yield.

The activation of 1,2‐diols through formation of boronate esters was found to enhance the selective oxidation of 1,2‐diols to their corresponding α‐hydroxy ketones in aqueous medium. The oxidation step was accomplished using dibromoisocyanuric acid (DBI) as a terminal chemical oxidant or an electrochemical process. The electrochemical process was based on the use of platinum electrodes, methylboronic acid [MeB(OH)2] as a catalyst and bromide ion as a mediator. Electro‐generated OH− ions (EGB) at the cathode acted as a base and “Br+” ion generated at the anode acted as an oxidant. Various cyclic and acyclic 1,2‐diols as substrates were selectively oxidized to the corresponding α‐hydroxy ketones via their boronate esters by the two oxidative methods in good to excellent yields.magnified image

Dimethyltin(IV)dichloride-catalyzed selective oxidation of 1,2diols in water was achieved using dibromoisocyanuric acid (DBI) or Br 2 as oxidants. The catalyst activates the 1,2-diol moiety through the formation of stannylene acetal in addition to 10 enhancing selectivity. Various cyclic and acyclic 1,2-diols substrates have been selectively oxidized affording αhydroxyketones in good to excellent yields. This method is safe and simple in operation.

An environmentally friendly electrochemical process for selective oxidation of 1,2-diols in water using Me 2 SnCl 2 catalyst, KBr as a bromide ion source and platinum electrodes has been developed. This method uses "Br + " ion, generated at the anode as an oxidant and OH − ion, at the cathode as an electro-generated base. Various cyclic and acyclic 1,2-diols were tolerated affording the corresponding α-hydroxyketones in moderate to high yields.

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