BackTwo stereoisomers of a bromodecalin are shown. Although the difference between these stereoisomers may seem trivial, one isomer undergoes elimination with KOH much faster than the other. Predict the products of these eliminations, and explain the large difference in the ease of elimination.
For which of the following reactions would you expect elimination to be more favored than substitution?
(c)
Explain how each of the following changes affect the rate of the reaction of 1-bromobutane with ethoxide ion in DMF.
c. The alkyl halide is changed to 1-chlorobutane.
d. The alkyl halide is changed to 2-bromobutane.
For each reaction, decide whether substitution or elimination (or both) is possible, and predict the products you expect. Label the major products.
c. chlorocyclohexane+NaOCH3 in CH3OH
d. chlorocyclohexane + NaOC(CH3)3 in (CH3)3COH
Given the reactants shown, what type of elimination would you expect to occur?
(a)
Four alkenes are formed from the E1 reaction of 3-bromo-2,3-dimethylpentane and methanol. Draw the structures of the alkenes and rank them according to the amount that would be formed.
Identify whether each of the following reactions proceed by an SN1 ,SN2 , E1, or E2 mechanism.
(a)
Suggest a bromoalkane and the conditions necessary to produce the alkenes shown.
(b)
Given the reactants shown, what type of elimination would you expect to occur?
(d)
Identify whether each of the following reactions proceed by an SN1, SN2, E1, or E2 mechanism.
(b)
Give the substitution and elimination products you would expect from the following reactions.
b. 1-iodo-1-phenylcyclopentane heated in ethanol
A small amount of another organic product is formed in a Williamson ether synthesis. What is this product when the alkyl halide used in the synthesis of butyl propyl ether is
b. butyl bromide?
Predict the product of the following reactions.
(b)
What are the products of the following reactions?
f.
Deuterium (D) is the isotope of hydrogen of mass number 2, with a proton and a neutron in its nucleus. The chemistry of deuterium is nearly identical to the chemistry of hydrogen, except that the C―D bond is slightly (5.0 kJ/mol, or 1.2 kcal/mol) stronger than the C―H bond. Reaction rates tend to be slower if a C―D bond (as opposed to a C―H bond) is broken in a rate-limiting step. This effect on the rate is called a kinetic isotope effect. (Review PROBLEM 4-57)
a. Propose a mechanism to explain each product in the following reaction.