Question

Would a SN1 reaction still occur if the following changes were made to the reaction? Assume all other conditions are kept the same as in experiment 5 . In each of your answers include: If a SN1 reaction STILL OCCURS: Draw the structure of the product and state its IUPAC name and compare the expected reaction rate to the one in experiment 5 (is it faster or slower?) If a SN1 reaction DOES NOT OCCUR: Include the type of mechanism (you do not need to draw it, just the name like SN1 ) that would happen and draw the structure of the product and state its IUPAC name.

a) We used 3-methyl-1-butanol instead of 2-methyl-2-butanol.
b) We used sulfuric acid (H2SO4) instead of hydrochloric acid.
c) We used 2,3-dimethylbut-2-en-1-ol instead of 2-methyl-2-butanol.

Answer 1

The SN1 reaction's feasibility depends on the substrate, acid, and conditions used. For 3-methyl-1-butanol, an SN2 reaction is more likely. Using H2SO4, SN1 might still occur with an increased rate. With 2,3-dimethylbut-2-en-1-ol, either SN1 or E1 could occur depending on the conditions.

Step-by-step explanation:

SN1 Reaction Analysis with Different Substrates and Conditions

For the SN1 reaction mechanism, the reaction rate and the possibility of a reaction occurring depend on the type of substrate, the solvent, and the nucleophile involved.

a) Using 3-methyl-1-butanol instead of 2-methyl-2-butanol

3-Methyl-1-butanol is a primary alcohol, which generally does not undergo SN1 reactions due to the higher energy and instability of the primary carbocation that would need to be formed. Therefore, an SN2 mechanism is more likely to occur instead of SN1. The product would be the corresponding bromide, 3-methyl-1-bromobutane, with the IUPAC name being the same.

b) Using sulfuric acid (H2SO4) instead of hydrochloric acid

Sulfuric acid can act as a strong acid in SN1 reactions, promoting the formation of the carbocation intermediate. The SN1 reaction is still likely to occur, and the product would be the same as in experiment 5, but since H2SO4 is a stronger acid than HCl, the reaction rate might increase.

c) Using 2,3-dimethylbut-2-en-1-ol instead of 2-methyl-2-butanol

This substrate has a tertiary alkyl group next to a double bond, which can stabilize the carbocation through resonance, making the SN1 mechanism viable. However, the presence of the double bond also makes an E1 elimination mechanism possible. If SN1 occurs, the product would be 3,3-dimethyl-1-butene, a racemic mixture due to the carbocation being planar.