Exam 7: Substitution Reactions: the Sn2 and Sn1 Reactions

The final step in the SN₁ reaction of water with tert-butyl bromide to form tert-butyl alcohol is the deprotonation of the oxonium ion to give the alcohol plus hydronium: The relative energies of the starting materials and products in this step are expected to be very similar. Explain why in practice this reaction proceeds essentially to completion.

Which of the following statements about Lewis acids and bases is false?

Which of the following compounds is the product of the reaction shown that displays retention of configuration compared to the starting material?

What sequence of reactions could be used for the following synthesis?

What is the most likely stereochemical outcome of the S_N1 reaction shown here?

For the reaction profile shown below, which statement(s) could be made? I.The transition state will look more like the starting materials than the products. II.The reaction is endothermic. III.The equilibrium constant for the forward reaction will be larger than 1. IV.The activation barriers for the forward and reverse reactions are equal.

Which of the following ideas best explains why S_N2 reactions proceed with inversion of configuration?

Outline a multistep synthesis of the target molecule from the starting material shown.You may use any organic or inorganic reagents.Show the reagents necessary for each step and the product of each step.

Identify the Lewis acid and the Lewis base in the reaction shown here.

An intramolecular Williamson ether synthesis may be used to produce epoxides.Predict the product of the following reaction conditions and provide a mechanism for the transformation.

Chemicals such as dimethyl sulfate and iodomethane are considered biologically hazardous because:

Which of the following electrophiles would undergo an S_N2 reaction with thiolate ion (HS^-) at the fastest rate?

Which of the following factors would not be expected to affect the entropy of a reaction?

Which of these carbocations is most stable?

Provide the missing reagents in the following reaction sequence.