Diels-Alder

1. EXPERIMENT #4 7/23/07 DIELS-ALDER REACTION

GRACE KIM MIKE HALL

2. INTRODUCTION AND PURPOSE A Diels-Alder reaction of 1,3-butadiene and aleic anhydride will be carried out to produce cyclohexene-cis-1,2dicarboxylic anhydride. The product will then be hydrolyzed to the diacid. Both the anhydride and the diacid will be tested via unsaturation tests and melting point determination. 3. MAIN REACTION & MECHANISMS

Diels-Alder reaction:

O H O

+

O

O

SO2

+

SO2

O H O

1 Hydrolysis:

O H OH O

2: 1,3-Butadiene

3: Maleic anhydride

4:4-Cyclohexene-cis-1,2dicarboxylic anhydride

O H OH2 O H

OH2 H

OH H OH O O O H

H OH OH H OH2 H

+

H O

H O

H O

H O

H COOH

COOH H

5: 4-Cyclohexne-cis1,2-dicarboxylic acid

4. TABLE OF REACTANTS & PRODUCTS Table of Reagents Diels-Alder Reaction: Structure # MW (g/ mol) Amounts Moles used theoretically mL grams used required ~5 3.28 -

Compound petroleum ether

Physical properties b.p = 60-800C flash point = -300C, density = 0.656 g/ mL

1

Xylene

318.501

11

9.48

-

-

3-sulfolene, C4H6O2S 1,3-Butadiene, C4H6 maleic anhydride, C4H2O3

1 2 3

118.150 54.0914 98.058

-

2.47 1.13 1.77

0.0209 0.0209 0.0181

0.0181 0.0181 0.0181

b.p. = 1400C flash point = 250C, water insoluble, solvent for rxn density = 0.862 g/ mL white, pale yellow crystal colorless gas colorless, white solid with penetrating odor, causes burns.

Limiting reagent = maleic anhydride Hydrolysis Reaction: Structure # 4 MW (g/ mol) 152.088 18.0 Amounts used grams 1.23 excess Moles theoretically Used required 0.00809 0.00809 -

Compound cyclohexene-cis-1,2dicarboxylic anhydride H2O Limiting reagent = anhydride Table of Products Compound cyclohexene-cis-1,2dicarboxylic anhydride 4-cyclohexene-cis-1,2dicarboxylic acid SO2

Physical properties m.p. = 103-1040C -

Structure # 4 5 -

MW (g/ mol) 152.088 168.088 64.0

Theoretical yield grams Moles 2.75 0.0181 1.36 13.38...