ALDEHYDES WITH ONE a-HYDROGEN ATOM 99 /3,/3-dimethyltrimethyleneglycol and hydroxypiyalic acid. 34 Pivalalde-hyde is only slightly affected by 50% aqueous alkali, but when treated with 50% alcoholic potassium hydroxide it yields 50-60% of neopentyl alcohol and pivalic acid. 36> 36 This apparently greater reactivity of the hydroxyaldehyde is to be attributed at least in part to its greater sol-ubility in 50% aqueous alkali. a-Hydroxyisobutyraldehyde undergoes smooth dismutation with dilute sodium or potassium hydroxide (3-10%) to yield isobutylene glycol and a-hydroxyisobutyric acid. 37-38 The same products can be obtained from a-bromoisobutyraldehyde, hydrolysis to the hydroxyaldehyde preceding the dismutation. Certain aliphatic aldehydes which have no hydrogen atoms on the a-carbon atom undergo cleavage under the influence of alkali. The con-version of a trihaloacetaldehyde to the haloform and the alkali formate is the best-known example. Triphenylacetaldehyde undergoes a similar cleavage, yielding triphenylmethane and the alkali formate. 38
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