3-Chlorobut-1-ene and 1-chlorobut-2-ene are each hydrolysed in water under conditions where the SN1 pathway operates. Which statement is correct (constitutional isomers only)?

A3-Chlorobut-1-ene gives only but-3-en-2-ol and 1-chlorobut-2-ene gives only but-2-en-1-ol
BBoth chlorides give only but-2-en-1-ol
CBoth chlorides give the same two alcohols, but-3-en-2-ol and but-2-en-1-ol
DBoth chlorides give only but-3-en-2-ol

Answer: C

Both chlorides ionise to the same resonance-stabilised allylic cation

CH X_{3} - CH X^{+} - CH = CH X_{2} CH X_{3} - CH = CH - CH X_{2} X^{+}

. Water can attack either terminus, so each chloride gives the same mixture of the secondary alcohol but-3-en-2-ol and the primary alcohol but-2-en-1-ol.

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3-Chlorobut-1-ene and 1-chlorobut-2-ene are each hydrolysed in water under conditions where the SN1 pathway operates. Which statement is correct (constitutional isomers only)?

Answer: C

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