a)
Interpretation:
Whether the electrocyclic reaction shown takes place in conrotatory or disrotatory manner is to be stated. The conditions, thermal or photochemical, under which the reaction can be carried out also is to be stated.
Concept introduction:
In elecrocyclic reactions involving even number of electron pairs, a thermal reaction occurs in conrotatory manner and a photochemical reaction occurs in disrotatory manner.
In elecrocyclic reactions involving odd number of electron pairs, a thermal reaction occurs in disrotatory manner and a photochemical reaction occurs in conrotatory manner.
b)
Interpretation:
Whether the electrocyclic reaction shown takes place in conrotatory or disrotatory manner is to be stated. The conditions, thermal or photochemical, under which the reaction can be carried out also is to be stated.
Concept introduction:
In elecrocyclic reactions involving even number of electron pairs, a thermal reaction occurs in conrotatory manner and a photochemical reaction occurs in disrotatory manner.
In elecrocyclic reactions involving odd number of electron pairs, a thermal reaction occurs in disrotatory manner and a photochemical reaction occurs in conrotatory manner.
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Chapter 30 Solutions
Organic Chemistry
- kcal ) at 298 K. Reaction B is ten million times faster moL kJ The standard free energy of activation of a reaction A is 79.0 (18.9 moL than reaction A at the same temperature. The products of each reaction are 10.0 (2.39 kcal) more stable than mol mol the reactants. (a) What is the standard free energy of activation of AG = kJ 44.77 reaction B? mol Incorrect (b) What is the standard free energy of activation of the AG ReverseA kJ 89 reverse of reaction A? mol (c) What is the standard free energy of activation of the AG ReverseB kJ 54.77 reverse of reaction B? moL Incorrectarrow_forwardIdentify the pericyclic reactions in the followingreaction schemes. Give the complete reaction name and indicate the course of the reaction with the aid of the arrow notation.arrow_forward(3) HI does not undergo free radical addition with 1-butene, even in the presence of a peroxide. Please provide an explanation by analyzing the propagation steps if the same radical reaction occurred with HI. Besides the bond dissociation enthalpies in the appendix, the following approximate bond dissociate enthalpies might be useful to you: ~310 kJ/mol The component of C=C CH3CH₂CH₂CH₂-Br CH3CH₂CH₂CH2-I -290 kJ/mol (C-Br bond) ~235 kJ/mol (C-I bond)arrow_forward
- (a) In the lab, you are required to synthesize the target molecule 1 from the starting material provided in the following scheme. Upon completion of the reaction however, the compound you obtained was product 2, by reacting the starting material with water in the presence of H2SO4: OH OH Product 2 Starting Material Target Molecule 1 Based on your observations and knowledge of chemistry, answer the following questions: (i) Outline a detailed reaction mechanism to clearly explain the formation of product 2. (ii) Justify why product 2 was formed. 2.arrow_forwardPredict the major product for the following electrocyclic reaction under two different conditions. For each reaction, shade the appropriate lobes of the entire orbita/ array and indicate the substituents at appropriate locations. For each reaction, indicate whether it is conrotatory, disrotaotry and show appropriate stereochemistry. (a) Under photochemical (b) Under Thermal بتشتر hv heatarrow_forwardExamine each of the following ALLOWED electrocyclic, sigmatropic or cycloaddition reactions. Determine in each of these how many electrons are involved. For electrocyclic and cycloaddition reaction, this includes π-electrons (4n or 4n+2); for sigmatropic reactions, one σ bond electrons also contribures. Tell what type of concerted reaction each is, and whether 4n or 4n+2 system. Thank you!arrow_forward
- 46arrow_forward(d) Consider the following catalyzed and non-catalyzed pathways of a substitution reaction of bromoethane. Draw an energy diagram for each of the following reactions (label all axes and include reactants, intermediates (if any) and products). CH3CH₂Br + HO CH³CH₂OH + B (non-catalyzed) ное CH3CH₂Br + CH3CH₂OH + 1 (catalyzed) CH3CH₂ + Brarrow_forwardGive the process of Determining the Mechanism and Stereochemistry inNucleophilic Substitution ?arrow_forward
- Provide the mechanism for the following reaction (1) PhMgBr (2 equiv) (2) H3O+ workup OHarrow_forward(b) Predict the major product (or products) formed when each of the following compounds 11- 14 reacts with a mixture of concentrated HNO3 and H2SO4. CO2H HN CO2H CI 11 12 13 14 (c) Pick one of the reactions under (b) and write the mechanism of the electrophilic aromatic substitution in detail (generation of the attacking electrophile is not required).arrow_forward11.; (a) Similar to alkanes, hydrogen gas can undergo radical bromination according to the reaction below. Propose a chain-reaction mechanism for this reaction, including an initiation step, propagation steps, and two plausible termination steps. The homolytic bond dissociation energy for Br-Br is 46 kcal·mole', for H-Br is 88 kcal'mole and for H-H is 104 kcal'mole'. hv H-H + Br-Br 2 H-Br (b) Calculate the overall AH for the above propagation steps (show all work).arrow_forward
- Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage LearningOrganic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning