Hydroxyketones dihydroxy-ketones

It is known that a-hydroxyketones are important as intermediates for organic synthesis. In order to increase the yield of an a-hydroxyketone we carried out a detailed investigation of the reaction conditions. The reaction of a-iodo- and o,a -diiodoketone using photoirradiation in alcohols, hexane, and acetone, etc. in the presence of air afforded the corresponding a-hydroxy- and a,a -dihydroxy ketones in good yield. 

Terminal alkyne anions are popular reagents for the acyl anion synthons (RCHjCO"). If this nucleophile is added to aldehydes or ketones, the triple bond remains. This can be con verted to an alkynemercury(II) complex with mercuric salts and is hydrated with water or acids to form ketones (M.M.T. Khan, 1974). The more substituted carbon atom of the al-kynes is converted preferentially into a carbonyl group. Highly substituted a-hydroxyketones are available by this method (J.A. Katzenellenbogen, 1973). Acetylene itself can react with two molecules of an aldehyde or a ketone (V. jager, 1977). Hydration then leads to 1,4-dihydroxy-2-butanones. The 1,4-diols tend to condense to tetrahydrofuran derivatives in the presence of acids. 

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