Diels-Alder Lab

Question 1

What is the name and structure of our diene?

Answer 1

Anthracene

Three cyclohexane rings in a honeycomb fashion, the first two have two double bonds, the last has three

Question 2

What is the name and structure of our dienophile?

Answer 2

Maleic Anhydride

Cyclopentene with an O replacing one of the hydrogens and adjacent to two double bonds to oxygens

Question 3

What is the name and structure of our solvent?

Answer 3

P-Xylene

Benzene ring with two methyl groups opposite

Question 4

What are the characteristics of a good diene?

Answer 4

Needs to be conjugated, stronger with more electron donating groups

Question 5

What are the characteristics of a good dieneophile?

Answer 5

Can have a double or triple bond, stronger with more electron withdrawing groups

Question 6

What is the general mechanism for a Diels-Alder reaction?

Answer 6

Electrons from double bond on dienophile connect to one of the double bonds of the diene, which pushes that double bond over and makes the electrons from the other double bond connect to the dienophile

Question 7

What is the stereochemistry of a Diels-Alder reaction?

Answer 7

Stereospecific: Syn Addition with retained configuration of the dienophile
May produce enantiomers
Diene only reacts in the c-cis conformation, if it is in the c-trans it will either change to c-cis or not react
Occurs primarily in an endo fashion (substituents are pointing inside of the largest ring)

Question 8

What (3) makes p-xylene a good solvent?

Answer 8

BP is good reaction temperature, does not freeze in ice bath, reactants are more soluble than the product which crystallizes