Concept explainers
Diels–Alder reaction of a monosubstituted diene (such as
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Organic Chemistry
- Mechanism The Diels-Alder reaction is part of a class of reactions known as a cycloaddition reaction. This reaction is specifically a [4+2] cycloaddition which is a concerted (one-step) process in which two new carbon - carbon sigma bonds are formed from two pi bonds. For the first Diels - Alder step of the mechanism fill in the arrows needed for the transformation. The rest of the mechanism is drawn for you. OH Show mechanism arrows for this step! 4 + 2 cycloaddition OH H D- & H+ transfer OH Nuc acyl substitution H L.G.arrow_forwardCompounds P and Q can undergo a Diels-Alder reaction to form two regioisomeric products R and S as shown in Figure 5. OMe O C8H12O2 R C8H12O2 S Figure 5 Draw the chemical structures of regioisomeric compounds R and S. Using possible resonance contributors of P and Q predict which of the two regioisomers will be favoured in the reaction. Using curly arrows, draw the mechanism for the reaction of P and Q to form the dominant regioisomer you have predicted in your answer to part (ii) above.arrow_forwardCyclobutane reacts with bromine to give bromocyclobutane, but bicyclobutane reacts with bromine to give 1,3-dibromocyclobutane. Account for the differences between the reactions of these two compounds. heat + Br2 -Br + HBr Cyclobutane Bromocyclobutane heat Br2 Br Br Bicyclobutane 1,3-Dibromocyclobutanearrow_forward
- Addition of HBr to allene (CH2 = C = CH2) forms 2-bromoprop-1-ene rather than 3-bromoprop-1-ene, even though 3-bromoprop-1-ene is formed from an allylic carbocation. Considering the arrangement of orbitals in the allene reactant, explain this result.arrow_forwardRank the following dienes in their rate of reaction with the same dienophile in a Diels-Alder reaction. For example, 1 = fastest or most reactive diene, 4 = slowest or least reactive diene.arrow_forwardThe product of this Diels Alder reaction would be called: H₂C O 1,3-cyclohexadiene O hexene O cyclohexene CH₂ O cyclohexane + CH₂ CH₂arrow_forward
- Chlordane, like DDT, is an alkyl halide that was used as an insecticide for crops such as corn and citrus and for lawns. In 1983, it was banned for all uses except against termites, and in 1988, it was banned for use against termites as well. Chlordane can be synthesized from two reactants in one step. One of the reactants is hexachlorocyclopentadiene. What is the other reactant?arrow_forwardThe compound below is treated with chlorine in the presence of light. H₂C CH3 H3C CH₂CH3 Draw the structure for the organic radical species produced by reaction of the compound with a chlorine atom. Assume reaction occurs at the weakest C-H bond. • You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms.arrow_forwardWhich diene is more reactive in a Diels–Alder reaction? CH2=CHCH=CHOCH3 or CH2=CHCH=CHCH2OCH3arrow_forward
- Define Electrophilic addition and the Hammond postulate ?arrow_forwardPlease show all arrow pushing mechanisais. Thank you!arrow_forwardDraw structural formulas for the diene and dienophile that combine in a Diels-Alder reaction to form the product shown. CH3O ● Diene + Dienophile -> Consider E/Z stereochemistry of alkenes. • Draw one structure per sketcher. Add additional sketchers using the drop-down menu in the bottom right corner. Separate multiple products using the + sign from the drop-down menu. ● Harrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning