Q4A) Draw a molecule that is capable of undergoing an electrocyclization reaction, in which the product has two chiral sp3 stereocenters. Then, draw the mechanism and product(s) for a photochemically induced electrocyclization reaction of your molecule.
Q4B) Now, draw a diagram showing all of the frontier MO of your reactant from Q2A and place the electrons in these MO in the ground state. We commonly use a combination of p orbitals to represent the MOs, complete with different lobes colored/shaded differently and nodes (example shown). We use additional horizontal lines to represent the energy levels for the different MOs and arrows to indicate presence of electrons in these MOs and energy levels (please see textbook or lecture slides for examples of these drawings). Use the labels HOMO and LUMO if appropriate.
Q4C) Now imagine your molecule has light shine upon it (i.e. is irradiated), and the characteristic of the light energy is sufficient to be absorbed by your molecule. This puts your molecule into a higher energy, excited state. Draw an accompanying diagram that shows the changes to the electrons in your frontier MO diagram upon photo excitation. Use the labels HOMO and LUMO if appropriate.
Q4D) On your diagram in Q2C (photoexcited state), draw a line that connects the two lobes of the appropriate MOs that will combine to make the new sigma bond that forms during the electrocyclization reaction.
Q4E) Based on Q2D, will your reaction go through a disrotatory or conrotatory mechanism?
Q4F) Could your reaction produce more than one stereoisomers?
th Q4A: Draw a molecule that is capable of undergoing an electrocyclization reaction, in which the product has two chiral spstrocenters, Then, draw the mechanism and product(s) of for a photochemically induced electrocyclization reaction of your molecule. Q4B: Now, draw a diagram showing all of the frontier MO of your reactant from Q2A and place the electrons in these MO in the ground state. We commonly use a combination of p orbitals to represent the MOs, complete with different lobes colored/shaded differently and nodes (example shown). We use additional horizontal lines to represent the energy levels for the different MOs and arrows to indicate presence of electrons in these MOs and energy levels (please see textbook or lecture slides for examples of these drawings). Use the labels HOMO p orbital and LUMO if appropriate. Q4C: Now imagine your molecule has light shine upon it (i.e. is irradiated), and the characteristic of the light energy is sufficient to be absorbed by your molecule. This puts your molecule into a higher energy, excited state. Draw an accompanying diagram that shows the changes to the electrons in your frontier MO diagram upon photo excitation. Use the labels HOMO and LUMO if appropriate. Q4D: On your diagram in Q2C (photoexcited state), draw a line that connects the two lobes of the appropriate MOs that will combine to make the new sigma bond that forms during the electrocyclization reaction. Q4E: Based on Q2D, will your reaction go through a disrotatory or conrotatory mechanism? Q4F: Could your reaction produce more than one stereoisomers? lobes shaded differently ith different lobeuntl of the frontier auedelectroction
