c with ondve 17-10 Deoxygenation of the Carbony Grou … hydrazones into 学名 the rc. w时 ner reduction aids in alkylbenzene 17-11 Addition of Hyr Cyanide to Give 1010 Condensations with secondary amines give enamines. Aldehydes and ketones react with secondary amines to produce enamines. In this reaction, water is eliminated between the hydroxyl group and the neighboring carbon atom, rather than the nitrogen atom. Enamine formation is reversible and hydrolysis occurs readily in the presence of aqueous acid. 17-10 Deoxygenation of the Carbonyl Group Strong base converts simple hydrazones into hydrocarbons. Hydrazones are formed from the condensation of an aldehyde or ketone with hydrazine. When treated with a base at elevated temperatures, hydrazones decompose, liberating the corresponding hydrocarbon and nitrogen gas. This reaction is known as the Wolff-Kishner reduction.(Wolff-Kishner-Minglong Huang reduction) In practice, the intermediate hydrazone is not isolated. Instead, it is generated in the presence of strong base and is used up as it is formed. Wolff-Kishner reduction aids in alkylbenzene synthesis. The Wolff-Kishner-Minglong Huang deoxygenation is frequently used in lieu of Friedel-Crafts alkanoylation, particularly for acid￾sensitive, base-stable substrates. Addition of Hydrogen Cyanide to Give Cyanohydrins 17-11 Hydrogen cyanide adds to the carbonyl group to form cyanohydrins. Slow addition of HCl to an excess of NaCN is typically used to generate HCN in a moderately alkaline mixture. This reaction requires the presence of both a free cyanide ion and undissociated HCN (satisfied by maintaining a moderately basic pH)