10. Addition Reactions

Draw the product(s) you'd expect when each of these alkenes is treated first with O₃, then with CH₃SCH₃

(a)

The following product was obtained from the ozonolysis of an alkene followed by treatment with dimethyl sulfide. What is the structure of the alkene?

c.

Show how you would synthesize each compound using methylenecyclohexane as your starting material.

(d)

What is the major product of the reaction of 2-methyl-2-butene with each of the following reagents?

d. O₃, −78 °C, followed by (CH₃)₂S

Predict the major products of the following reactions.

(c)

(d) 1-ethylcycloheptene + ozone, then (CH₃)₂S

Draw the product(s) you'd expect when each of these alkenes is treated first with O₃, then with CH₃SCH₃

(d)

One of the constituents of turpentine is α-pinene, formula C₁₀H₆. The following scheme (called a “road map”) gives some reactions of α-pinene. Determine the structure of α-pinene and of the reaction products of A through E.

Ozonolysis of an alkene, followed by treatment with dimethyl sulfide, forms the following product(s). Identify the alkene in each case.

b.

For each compound, show the products obtained from ozonolysis, followed by treatment with dimethyl sulfide.

d.

Problem 8-54 describes a new method to perform ozonolysis reactions that used pyridine (py) to generate the final aldehydes and ketones in a non-aqueous reaction medium. In a subsequent publication (J. Org. Chem., 2013, 78, 42), Professor Dussault (U. of Nebraska at Lincoln) described a “tandem” process in which two reactions are performed sequentially without having to isolate the intermediate aldehyde or ketone. Show the final product from each sequence. (Hint: The isolated products were from the larger part of the structure. Ignore stereochemistry.)

(a)

(b)

Which of the following compounds is formed by ozonolysis of $2-\mathrm{butyne}$?

Formation of the molozonide can be expected to proceed stereospecifically. Why is this the case? Show the two different molozonides you would expect to get from ozonolysis of (E)- and (Z)-3,4-dimethylhept-3-ene.

What alkene gives the product shown after reaction first with ozone and then with dimethyl sulfide?

a.

In contact with a platinum catalyst, an unknown alkene reacts with three equivalents of hydrogen gas to give 1-isopropyl-4-methylcyclohexane. When the unknown alkene is ozonized and reduced, the products are the following:

Deduce the structure of the unknown alkene.

Give structures of the alkenes that would give the following products upon ozonolysis–reduction.

(b)