5. Pericyclic Reactions (2/5 - Sigmatropic Rearrangements)

Question 1

Draw the mechanism for the [3,3]-Cope rearrangement of 1,5-diene.

Answer 1

Question 2

Draw the mechanism for the [3,3]-Claisen rearrangement of an allyl vinyl ether.

Answer 2

Question 3

Draw the chair like transition states of this [3,3]-sigmatropic rearrangement.

Answer 3

Question 4

Answer 4

Question 5

Draw the structures of the substrate from their boat-like transition states.

Answer 5

Question 6

For the [3,3]-sigmatropic rearrangement of 1,5-diene, draw the chair-like transition states and molecular orbital diagrams.

Answer 6

Question 7

Of the following [1,n]-hydride shifts: [1,3], [1,5], [1,7], indicate which occur under heat, the plan on which H migrates as well as predict which will be supra/antarafacial.

Answer 7

Question 8

With use of molecular orbital diagrams, justify why [1,3]-hydride shift doesn’t occur under heat.

Answer 8

Question 9

With use of molecular orbital diagrams, justify why [1,5]-hydride shift does occur under heat.

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12