The reaction of an alkyl halide with potassium cyanide is synthetically useful because it
Correct answer: C. lengthens the carbon chain by one carbon atom
- A. shortens the carbon chain by one atom
- B. produces an alkene
- C. lengthens the carbon chain by one carbon atom
- D. removes the halogen without adding anything
Explanation
The cyanide ion substitutes for the halogen, so the nitrile formed has one more carbon than the starting halide, and that nitrile can then be hydrolysed to a carboxylic acid or reduced to an amine. Building the chain one carbon at a time is a standard strategy in organic synthesis. Alcoholic conditions are used to favour substitution over elimination.
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About Nucleophilic Substitution
Nucleophilic substitution replaces a leaving group in an alkyl halide when an electron-rich nucleophile attacks the carbon atom. The topic compares SN1 and SN2 mechanisms, including reaction conditions, substrate structure, solvent effects, nucleophile strength, carbocation formation and stereochemical changes, and distinguishes substitution from elimination.
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