
(a)
Interpretation: MOs for the given conjugated systems has to be drawn and the HOMO has to be predicted as symmetric or antisymmetric.
Concept introduction:
Conjugated system: A system of connected p-orbitals with delocalized electrons with alternating single and multiple bonds and the compound may be cyclic, linear or mixed.
Molecular orbital theory suggests that atomic orbitals of different atoms combines to create molecular orbitals.
Molecular orbitals can be constructed from linear combination of atomic orbitals.
Bonding orbotals are formed by the additive combination of atomic orbitals and the antibonding orbitals are formed by the substractive combination of atomic orbitals.
Antibonding orbital is a molecular orbital that results when two parallel atomic orbitals with opposite phases interact.
Antibonding orbitals have higher energy than the bonding molecular orbitals.
Ground state and and exited states are the positions with lower and higher energy respectively.
HOMO is a molecular orbital which is the abbrevation of Highest Occupied Molecular Orbital.
LUMO is also a molecular orbital which is the short form of Lowest Unoccupied Molecular Orbital.
If the lobes at the ends of the MO are in phase, then the MO is symmetric.
If the two lobes are out phase then the MO is antisymmetric.
Woodward –Hoffmann rules are the set of rules used to vindicate or predict certain aspects of the stereo chemical outcome and activation energy of pericyclic reactions.
Woodward – Hoffmann rules for Electrocyclic reactions are listed below
(b)
Interpretation: The validity of Woodward – Hoffmann rule for an electrocyclic reaction has to be checked using the MOs of given systems.
Concept introduction:
Woodward –Hoffmann rules are the set of rules used to vindicate or predict certain aspects of the stereo chemical outcome and activation energy of pericyclic reactions.
Woodward – Hoffmann rules for Electrocyclic reactions are listed below

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Chapter 28 Solutions
Organic Chemistry; Modified MasteringChemistry with Pearson eText -- ValuePack Access Card; Study Guide and Student Solutions Manual for Organic Chemistry, Books a la Carte Edition (7th Edition)
- Would the following organic synthesis occur in one step? Add any missing products, required catalysts, inorganic reagents, and other important conditions. Please include a detailed explanation and drawings showing how the reaction may occur in one step.arrow_forward(a) Sketch the 'H NMR of the following chemical including the approximate chemical shifts, the multiplicity (splitting) of all signals and the integration (b) How many signals would you expect in the 13C NMR? CH3arrow_forwardDraw the Show the major and minor product(s) for the following reaction mechanisms for both reactions and show all resonance structures for any Explain why the major product is favoured? intermediates H-Brarrow_forward
- 3. Draw ALL THE POSSBILE PRODUCTS AND THE MECHANISMS WITH ALL RESONANCE STRUCTURES. Explain using the resonance structures why the major product(s) are formed over the minor product(s). H₂SO4, HONO CHarrow_forward7. Provide the product(s), starting material(s) and/or condition(s) required for the No mechanisms required. below reaction HO + H-I CI FO Br2, FeBr3 O I-Oarrow_forward6. Design the most efficient synthesis of the following product starting from phenot Provide the reaction conditions for each step (more than one step is required) and explain the selectivity of each reaction. NO MECHANISMS ARE REQUIRED. OH step(s) CIarrow_forward
- What is the skeletal structure of the product of the following organic reaction?arrow_forwardIf a reaction occurs, what would be the major products? Please include a detailed explanation as well as a drawing showing how the reaction occurs and what the final product is.arrow_forwardWhat is the major organic product of the following nucleophilic acyl substitution reaction of an acid chloride below?arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
