Concept explainers
Interpretation:
Theproducts formed from Diels Alder reaction of (2Z,4Z)-hexa-2,4-diene with methyl propenoate are to be determined.
Concept introduction:
A Diels Alder reaction is one between a conjugate diene and a reactant containing a double bond (dienophile) to form a product. The product is called adduct.
Diels Alder reactions are highly stereospecific. The configuration of the dienophile is retained in the product and the reaction is a syn addition reaction.
The dienes react with dienophiles in cis forms rather than trans forms.
Endo and exo refer to the orientation of the dienophile and its electron-withdrawing group when it reacts with a diene in a Diels Ander reaction.
Endo is favored in the transition state of aDiels Ander reaction because it has a lower energy.
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EBK ORGANIC CHEMISTRY
- Draw the reactants that would react to form this cyclohexene derivative in a Diels-Alder reaction. Include any relevant stereochemical configurations. Draw Diene ✔ Iarrow_forwardFor the following dienes, identify whether the molecules has any cis or trans stereochemistry and idenfity the conformation as either s-cis or s-trans, where appropriate. Please also note whether the compound would be reactive in a Diels -Alder reactionarrow_forwardFrom trans-1-chloro-2-isopropylcyclohexane, only 3-isopropylcyclohexene, the less substituted alkene, is formed. Using conformational analysis, explain why this product is observed. Also, will the E2 reaction with trans-1-chloro- 2-isopropylcyclohexane or cis-1-chloro-2-isopropylcyclohexane occur faster under the same basic conditions? CH;O Na* CH3OH CI trans-1-Chloro-2 (R)-3-Isopropylcyclohexene isopropylcyclohexanearrow_forward
- Draw the reactants that would react to form this cyclohexene derivative in a Diels-Alder reaction. Include any relevant stereochemical configurations. Qarrow_forwardUsing one or more of the following compounds as starting materials or products illustrate, with an example, each of the following type of pericyclic reactions. Your answer should include curved arrow mechanisms. (i) a disrotatory thermal electrocyclic reaction (ii) a conrotatory photochemical electrocyclic reaction (iii) a [4+2] cycloaddition (iv) a [3,3]-sigmatropic rearrangementarrow_forward(a) Complete the following sequence of reactions (i.e., give the structure for compounds A and B), giving structural details of all key intermediates. heat & A COOCH3 H₁₂ Ni (b) Provide the bond line structures for the pair of compounds used for the Diels-Alder synthesis of the compound shown below. O B COOCH3 (c) Draw the two major products obtained when (3E,5Z)-2,2,3,6,7-pentamethylocta-3,5-diene reacts with HBr at low and high temperatures. Label the products as the kinetic or thermodynamic product AND, if applicable, use dashes and wedges to show the correct stereochemistry in the obtained products.arrow_forward
- A solution of 5-methylcyclopenta-1,3-diene rearranges at roomtemperature to a mixture containing 1-methyl-, 2-methyl-, and 5-methylcyclopenta-1,3-diene. (a) Show how both isomeric products areformed from the starting material by a sigmatropic rearrangementinvolving a C–H bond. (b) Explain why 2-methylcyclopenta-1,3-diene isnot formed directly from 5-methylcyclopenta-1,3-diene by a [1,3]rearrangement.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_forward5.) Given the following three reactions of enantiomerically pure starting materials, please identify products A and B for each line (given the product molecular formulae), using dashes and wedges where appropriate, the meso (optically inactive) product and the chiral (optically active product). NaBH4 CH3OH A CHo02 + B CSH1002 optically active HO optically inactive (R)-3-hydroxycyclopentanone OH Os04 (cat) (CH3)3COOH C CH1203 optically inactive + D CH1203 (2R, 3E)-2-hydroxy-3-pentene optically active OH Os04 (cat) (CH3)3COOH E CsH203 + F CSH1203 optically active optically inactive (2R, 3Z)-2-hydrox y-3-pentenearrow_forward
- (a) When cis-1-bromo-2-methylcyclohexane undergoes an E2 reaction, two products (cycloalkenes) are formed. What are these two cycloalkenes, and which would you expect to be the major product? Write conformational structures showing how each is formed. (b) When rans-1-bromo-2-methylcyclohexane reacts in an E2 reaction, only one cyclo- alkene is formed. What is this product? Write conformational structures showing why it is the only product.arrow_forward[3] Reaction of either 3-bromo-1-butene or (Z)-1-bromo-2-butene with water under S,1 condition yields the same product. Explain whyarrow_forward(i) Decide which the following compounds will react faster in an E2 reaction; trans-1-bromo-2-isopropylcyclohexane or cis-1-bromo-2-isopropylcyclohexane. (ii) Explain your answer.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning