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)

What products are formed when the following compounds react with ozone and then with dimethyl sulfide?

c.

d.

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

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?

b.

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.

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.)

(c)

(d)

Deduce the structure of each compound from the information given. All unknowns in this problem have molecular formula C₈H₁₂.

(c) Upon catalytic hydrogenation, unknown Y gives cyclooctane. Ozonolysis of Y, followed by reduction with dimethyl sulfide, gives a three-carbon dialdehyde and a five-carbon dialdehyde. Draw the structure of Y.

(d) Upon catalytic hydrogenation, unknown Z gives cis-bicyclo[4.2.0]octane. Ozonolysis of Z, followed by reduction with dimethyl sulfide, gives a cyclobutane with a three-carbon aldehyde (–CH₂–CH₂–CHO) group on C1 and a one-carbon aldehyde (–CHO) group on C2. Draw the structure of Z.

Predict the major products of the following reactions, and give the structures of any intermediates. Include stereochemistry where appropriate.

(d)

Professor Patrick Dussault (University of Nebraska at Lincoln) has developed an alternative to the standard two-step ozonolysis procedure requiring reduction of the ozonide in a second step. He uses 2 to 3 equivalents of pyridine, a mildly basic organic solvent, in a one-step process (Organic Letters, 2012, 14, 2242). Show the products you expect from the following examples.

(a)

(b)