1 Chloro 2 Methylpropane Sn1 Or Sn2

Question: The 6 alkyl halides used

Answer: 1) 1-chlorobutane

2) 2-chlorobutane

3) Allyl chloride

4) 2-chloro-2-methylpropane

5) 1-chloro-2-methylpropane

6) 2-bromobutane

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Question: 2 of the 6 alkyl halides CANNOT react via SN1 mechanism.

Which are they and why?

Answer: 1-chlorobutane and 1-chloro-2-methylpropane dont react with SN! mechanisms.

They for primary halides which form primary carbocations. These carbocations are unstable and cannot successfully occur in SN1.

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Question: 1 of the 6 alkyl halides reacts RAPIDLY via both SN1 and SN2 mechanisms.

Which is it and why?

Answer: Allyl chloride reacts with BOTH SN1 and SN2 mechanisms.

It forms a stable carbocation that is better than that of a primary one (SN1 favors) and the protons from the non-double bonded Carbons are highly acidic (SN2 favors).

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Question: 1 of the 6 alkyl halides is essentially unreactive via EITHER SN1 and SN2 mechanisms.

Which is it and why?

Answer: 1-chromobutane

It is a primary carbocation so it cannot react in an SN1 reaction.

It also has a POOR leaving group in Chloride so it cannot react in SN2.

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Question: Why did we use acetone as solvent for SN2 reactions?

Answer: Acetone is polar and aprotic. Both these conditions highly favor SN2 and cause sodium chloride and sodium bromide to precipitate whilst sodium iodidie is just soluble.

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Question: Why did we use ethanol as solvent for SN1 reactions?

Answer: Ethanol is highly polar and is protic. This allows ethanol to stabilize the carbocations that form in the first step of SN1 reactions.

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Question: Allyl chloride is carcinogenic. Draw a plausible reaction of allyl chloride with cytosine.

Based on the results of this experiment, explain why allyl chloride is carcinogenic but 2-chlorobutane is not.

Answer: draw reaction of allyl chloride with cytosine

Allyl chloride is much more SN2 reactive, so it is carcinogenic. 2-chlorobutane is not as SN2 reactive so it cannot be carcinogenic.

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