Ketocarboxylic acids hydroxycarboxylic acid

Furthermore these reagents can attack ethers, double bonds and aromatic rings in more functionalized compounds. The nickel hydroxide electrode is a suitable reagent to overcome these difficulties The necessary alkaline electrolyte opens the lactone ring to the oxidizable hydroxycarboxylate. The nickel hydroxide electrode tolerates double bonds, ethers and aromatic rings and leads in good to excellent yields to ketocarboxylic acids (Eq. (6), Table 11). 

Hydridospirophosphorane (60 Y = CH2, Z = H) in the presence of a tertiary amine has been used to convert ketocarboxylic acids such as pyruvates into the corresponding a-hydroxycarboxylates <92PS(70)263>. However in aqueous alcohol hydridophosphoranes such as (99 X = Glc, Y = Amc, Z = H) are converted to phosph(III)olanes <80PS(9)183>. 

Hydroxycarboxylic aeids and lactones from ketocarboxylic acids Steric control... 

Use of RuOj/aq. Na(IO )/CCl to oxidise the secondary alcohol function in hydroxylactones gave ketolactones, while lactones gave ketocarboxylates [201-203], The former reaction is exemplified by 5-ejco-enrfo-dihydroxybicyclo[2.2.1] heptane-2-e (i(9carboxylic acid-y-lactone giving the 5-keto-6-endo product (Fig. 2.9). A number of other hydroxylactones were similarly oxidised, as were y- or 5-hydroxycarboxylates to ketocarboxylates [201]. 

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