The Reactions of Carbonyl Compounds with Hydride Ion

Explain why aldehydes and ketones react with a weak acid such as hydrogen cyanide but do not react with strong acids such as HCl or H2SO4 (other than being protonated by them). 

How can the following compounds be prepared from a carbonyl compound that has one less carbon than the desired product  

Solution to 18a The starting material for the synthesis of this two-carbon compound must be formaldehyde. Addition of hydrogen cyanide followed by addition of H2 to the triple bond of the cyanohydrin forms the target molecule. 

Show two ways to convert an alkyl halide into a carboxylic acid that has one more carbon than the alkyl halide. 

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