Concept explainers
Interpretation:
Detailed mechanism of hydrobromination via 1,2-addition and 1,4-addition mechanisms using peroxide promoted addition to 1,3-butadiene are to be written.
Concept introduction:
舧 Electrophiles are electron-deficient species, which has positive or partially positive charge. Lewis acids are electrophiles, which accept electron pair.
舧 Nucleophiles are electron rich species, which has negative or partially negative charge. Lewis bases are nucleophiles, which donate electron pair.
舧 Free radical is an atom, molecule, or ion that has an unpaired electron, which makes it highly chemically reactive.
舧 Substitution reaction: A reaction in which one of the hydrogen atoms of a hydrocarbon or a
舧 Elimination reaction: A reaction in which two substituent groups are detached and a double bond is formed is called elimination reaction.
舧 Addition reaction: It is the reaction in which unsaturated bonds are converted to saturated molecules by the addition of molecules.
舧 The reaction in which there is addition of hydrogen molecule is called hydrogenation reaction.
舧
舧 Hydrogenation with platinum as a catalyst is used to convert unsaturated carbohydrates to saturated hydrocarbons
舧 Oxidation of
舧 Ozonolysis helps convert the carbon–carbon double bonds to carbon–oxygen double bond (carbonyl compounds).
舧 Dimethyl sulfide is used as a reducing agent that decomposes the intermediate formed into the carbonyl group.
舧 NBS (nitro-bromo succinimide) is a special reagent used for bromination of allylic carbocations.
舧 Bromine replaces the hydrogen attached to the carbon adjacent to the carbon bearing double bond.
舧 This method of using NBS can produce allylic bromides without bromine reacting with the double bond.
舧 Dehydration of a primary alcohol in the presence of a mineral acid like concentrated sulfuric acid results in the formation of alkene via E2 elimination
舧 The 1,2–addition to a diene is addition of an electrophile to the carbon designated as 1 and a nucleophile to the carbon designated as 2. The positions of carbons as 1 and 2 are not according to the IUPAC numbering of the molecule, but as a conjugated diene molecule. 1,4-addition results in addition of hydrogen to the carbon designated as 1 and a halogen to the carbon designated as 4. The mechanism of 1,2 addition and 1,4-addition of hydro halogenation is given below.
舧 Organic peroxides are used in free radical chain reactions in the initiation steps.
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Chapter 13 Solutions
Organic Chemistry
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- 4. 3-chloro-1-butene reacts with sodium ethoxide in ethanol to produce 3- ethyoxy-1-butene. In the absence of sodium ethoxide, 3-chloro-1-butene reacts with ethanol to produce both 3-ethoxy-1-butene and 1-ethoxy-2-butene. Explain these results. Be sure to include mechanisms and structures in your explanation. H. CH2=CH-C-CH3 ÓCH,CH3 GH,-CH=C-CH3 ÓCH,CH, 3-Ethoxy-1-butene 1-Ethoxy-2-butenearrow_forwardThe diene lactone shown in part (a) has one electron-donating group (¬OR) and one electron-withdrawing group(C“O). This diene lactone is sufficiently electron-rich to serve as the diene in a Diels–Alder reaction.(a) What product would you expect to form when this diene reacts with methyl acetylenecarboxylate, a strong dienophile?arrow_forwardSelect the correct isomer of 2-bromo-4-isopropyl-1-methylcyclohexane that, when subjected to ethoxide followed by hydrogenation, would yield a single isomer of 4-isopropyl-1- methylcyclohexane.arrow_forward
- 4.35 Formulate the reaction of cyclohexene with (i) Br2 and (ii) meta-chloro- peroxybenzoic acid followed by H30+. Show the reaction intermediates and the final products with correct cis or trans stereochemistry. 4.36 What products would you expect to obtain from reaction of cyclohexa- 1,3-diene with each of the following? (a) 1 mol Br2 in CH2C12 (c) 1 mol DCl (D = deuterium, ²H) (b) 1 mol HCl (d) 2 mol H2 over a Pd catalyst 4.37 Predict the products of the following reactions on hex-1-yne: (a) 1 equiv HBr ? (b) 1 equiv Cl2 ? (c) H2, Lindlar catalystarrow_forwardWhat are the expected kinetic and thermodynamic products from addition of one mole of Br, to the following dienes? (a) (Б)arrow_forwardThe following triene undergoes an intramolecular Diels-Alder reaction to give a bicyclic product. Propose a structural formula for the product. Account for the observation that the Diels-Alder reaction given in this problem takes place under milder conditions (at lower temperature) than the analogous Diels-Alder reaction 0"C Diels-Alder adductarrow_forward
- Determine all of the products obtained from the addition of HCl to the 1,3-diene. Once determined, draw a mechanism that accounts for the formation of every product. Then, Identify and account for the formation of the major adduct/or adducts under these conditions assuming that the reaction is conducted under thermodynamic conditions.arrow_forwardStep 6: Now that you have determined the substrates and mechanism of a Diels-Alder reaction, you will learn how to recognize when you should use the Diels-Alder reaction. In a synthesis reaction, if you are given a cyclohexene product with no other obvious functional group transformations and an electron-withdrawing group two carbons away from the alkene, it is likely made via the Diels-Alder reaction. Deduce the structures of the starting materials to form the Diels-Alder adduct shown. ..... CN CN Diene + Dienophilearrow_forward14. Please write the major product for each following Diels-Alder reaction. Explain why they are formed by using Frontier Molecular Orbital theory. (a) 1-(diethylamino)-1,3-butadiene + acrylate (b) 2-ethoxy-1,3-butadiene + acrylate Moreover, draw Molecular Orbitals of 1-(diethylamino)-1,3-butadiene, 2-ethoxy-1,3-butadiene & acrylate. In addition, mark energy levels and predict the products by using FMO theory.arrow_forward
Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning