1

Solutions to Problems Condensation Reactions

Building Bridges to Knowledge

Photo the Shanghai Shoreline

1. Suggest products for (a) - (f), and suggest IUPAC names for the products of (a) - (e).

(a)

3-hydroxybutanal

2

(b)

3-hydroxy-2-methylbutanal (c)

2-ethyl-3-hydroxybutanal (d)

3-hydroxy-2-methyl-3-phenylpropanal

3

(e)

2,4-dicyclohexyl-3-hydroxybutanal

(f)

4

2. Suggest a synthesis for the following compound from the indicated starting material and any necessary organic or inorganic materials.

5

3. Suggest a synthesis for the following compound from the

indicated starting materials and any necessary inorganic materials.

6

4. The following sequence of reactions leads to the formation of compound I.

Compound I

7

mechanism for the formation of compound A. (1)

(2)

5. Suggest a product for the following reaction, and

8

suggest a mechanism for the reaction. (1)

(2)

9

(3)

(4)

(5)

6. Suggest a series of elementary steps to rationalize the formation of

the following transformation.

10

The balanced chemical equation for the base-catalyzed reaction is:

(1)

+ H2O (2)

(3)

11

(4)

+ - OH 7. Suggest a mechanism for the following transformation.

The balanced chemical equation is:

12

(1)

+ H2O (2)

8. Suggest a mechanism for the following acid catalyzed reaction.

(1)

13

(2)

(3)

(4)

14

(5)

(6)

8. Using the cyclohexane-like chair conformation, suggest a

series of elementary steps to rationalize the following transformation.

15

(1)

+ H2O (2)

(3)

The formation of the double bond (the elimination reaction) would proceed through the following steps: (1)

(2)

16

(3)

10, Suggest a synthesis for the following from the indicated starting

material and any other necessary organic or inorganic compounds.

Step 1

17

Step 2: treat the resulting beta hydroxy ketone with acid and heat to form the elimination product.

18

11. Suggest structures for A, B, C6H12O2

19

12. Suggest a synthesis for Compound III from compound I,

compound II and any necessary inorganic materials.

compound III

compound I compound II

20

13. Yotes and Anderson reported the following transformation in the Journal of the American Chemical Society.

The reaction takes place in two steps. Step 1 is treatment with base:

21

Step 2 is acidification of the resulting salt:

Suggest a series of elementary steps that could account for this transformation. (1)

(2)

22

(3)

(4)

(5)

23

(6)

(7)

(8)

(9)

24

After the salt is formed, then it is acidified to form the carboxylic acid.