(a)
Interpretation:
A mechanism should be proposed for the given reaction.
Concept introduction:
Pericyclic reactions are “ any concerted reaction in which bonds are formed or brocken in a cyclic transition state”. There is a single transition state from start to finish, in contrast to a stepwise reaction.
In an electrocyclic reaction “one new sigma- bond is formed or brocken.”
Diels-alder reaction is a cycloaddition reaction which is occurs between a conjugated diene and substituted
Mechanism gives the step wise processes occurs in a particular reaction.
(b)
Interpretation:
The product should be determined for the given reaction if trans-2-butene were used instead of ethene.
Concept introduction:
Pericyclic reactions are “ any concerted reaction in which bonds are formed or brocken in a cyclic transition state”. There is a single transition state from start to finish, in contrast to a stepwise reaction.
In an electrocyclic reaction “one new sigma- bond is formed or brocken.”
Diels-alder reaction is a cycloaddition reaction which is occurs between a conjugated diene and substituted alkene to form cyclohexene ring system. This concerted reaction can be accelerated by heating or using some catalysts.
Mechanism gives the step wise processes occurs in a particular reaction.
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Organic Chemistry (8th Edition)
- In the alkene below, why is HB more easily abstracted by a halogen atom than HẠ ? НА HB A. Abstraction of Hg forms a carbocation, while abstraction of HA forms an carbanion. B. Abstraction of HB produces a more stable free radical. C. HB is abstracted as a stable H* ion, but HA is not. D. Abstraction of HB involves less steric hindrance.arrow_forward2. Predict the product(s) of the following Diels-Alder reactions. Be sure to consider regio- and stereochemistry. MeO MeO. Aarrow_forwarda. How many alkenes could you treat with H2, Pd/C to prepare methylcyclopentane? b. Which of the alkenes is the most stable? c. Which of the alkenes has the smallest heat of hydrogenation?arrow_forward
- Draw the products of the following Diels–Alder reactions. Indicate stereochemistry where appropriate and show the pushing mechanism for a and barrow_forwardName each alkene and specify its configuration by the E,Z system. Cl- Cl I a. b. Br С.arrow_forwardCompounds containing triple bonds are also Diels–Alder dienophiles. With this in mind, draw the products of each reaction.arrow_forward
- 6. Provide the reagents or the product for the following reactions. Br a b. HO он C. PB13arrow_forwardWhich stereoisomer would be produced from the reaction of trans-2-butene with OsO4 followed by H2O2? A. 2S,3S- diol and 2R, 3R-diol B. 2S,3R-diol and 2R,3S-diol C. 2S,3S-diol only D. 2R, 3R-diol only E. 2S,3R-diol onlyarrow_forwardPlease help with these Diels Alder reactions. Explain briefly!arrow_forward
- Identify the expected major product of the following Diels-Alder reaction. Showmechanism.arrow_forwardWhat stereoisomers are obtained from the following reactions? a. 1-butene + H2O + H2SO4 b. cyclohexene + HBr c. cis-3-heptene + Br2 d. trans-3-hexene + Br2arrow_forwardDraw the products of the following reactions. If the products can exist as stereoisomers show what stereoisomers are formed. a. cis-2-pentene + Br2/CH2Cl2 b. trans-2-pentene + Br2/CH2Cl2 c. 1- butene + HCl d. methylcyclohexene + HBr e. trans-3-hexene + Br2/CH2Cl2 f. cis-3-hexene + Br2/CH2Cl2 g. 3,3-dimethyl-1-pentene + HBr h. cis-2-butene + HBr i. (Z)-2,3-dichloro-2-butene + H2, Pd/C j. (E)-2,3-dichloro-2-butene + H2, Pd/C k. (Z)-3,4-dimethyl-3-hexene + H2, Pd/C l. (E)-3,4-dimethyl-3-hexene + H2, Pd/Carrow_forward
- Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning