1. Three (03) students are planning to run Diels-Alder reactionsusing maleic anhydride as dienophile and three (03) differentdienes (A, B, and C). Student A will be using cyclopenta-1,3-diene(compound A), Student B will be using buta-1,3-diene (compound B)and student C will be using 1,2,3,7,8,8a-hexahydronaphthalene(compound C).
- Draw the reaction schemes for Student A, Student B and StudentC using the above given starting materials (write “NO REACTIONâ€whenever the reaction is impossible).
Student A’s reaction scheme (2 pts)
Student B’s reaction scheme (2 pts)
Student C’s reaction scheme (2 pts)
- Which of the three reactions would you expect to be thefastest? Why?(2 pts)
- Student A would have to crack the cycolpentadiene before it canbe used, while student B will use the butadiene as purchased;explain why? (4 pts)
(d). Why is maleic anhydride a much better dienophile thanethylene (CH2=CH2)? (2 pts)
(e). When producing Diels-Alder adducts using maleic anhydrideas the dienophile, why is it important that reagents and apparatusbe dry? (2 pts)
(f). Why is Diels-Alder reaction exothermic process? Explainconsidering bond cleavage and bond formation contribution to theenthalpy change (2 pts)
