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(a)
Interpretation:
How the given compound with specified stereochemistry can be produced from an
Concept introduction:
A cyclopropyl group can be introduced in a compound by reacting the corresponding alkene (or
The stereochemistry of the double bond is preserved in the reaction as it is a concerted addition. If the alkene has a cis configuration, the two similar substituents on the double bond end up on the same side of the cyclopropyl ring in the product. If it is a trans alkene, the similar substituents on the double bond end up on opposite sides of the ring in the product.
Carbenes are generated in situ, typically by irradiating a mixture of the alkene and diazomethane with UV light or by treating a mixture of the alkene and haloform (trihalomethane) with a strong base like an alkoxide.
(b)
Interpretation:
How the given compound with specified stereochemistry can be produced from an alkene is to be shown along with the reagents used and special conditions if any.
Concept introduction:
A cyclopropyl group can be introduced in a compound by reacting the corresponding alkene (or alkyne) with a carbene. A carbene is a species with only two groups, typically hydrogen or halogen atoms bonded to a carbon. The carbon atom also carries a lone pair of electrons or sometimes two unpaired electrons. This pair of electrons makes the carbene extremely reactive. Carbenes add to an alkene or alkyne by simultaneously forming bonds with the two carbon atoms from the double (or triple) bond. One bond is formed by the lone pair on the carbene and the other by the
The stereochemistry of the double bond is preserved in the reaction as it is a concerted addition. If the alkene has a cis configuration, the two similar substituents on the double bond end up on the same side of the cyclopropyl ring in the product. If it is a trans alkene, the similar substituents on the double bond end up on opposite sides of the ring in the product.
Carbenes are generated in situ, typically by irradiating a mixture of the alkene and diazomethane with UV light or by treating a mixture of the alkene and haloform (trihalomethane) with a strong base like an alkoxide.
(c)
Interpretation:
How the given compound with specified stereochemistry can be produced from an alkene is to be shown along with the reagents used and special conditions if any.
Concept introduction:
A cyclopropyl group can be introduced in a compound by reacting the corresponding alkene (or alkyne) with a carbene. A carbene is a species with only two groups, typically hydrogen or halogen atoms bonded to a carbon. The carbon atom also carries a lone pair of electrons or sometimes two unpaired electrons. This pair of electrons makes the carbene extremely reactive. Carbenes add to an alkene or alkyne by simultaneously forming bonds with the two carbon atoms from the double (or triple) bond. One bond is formed by the lone pair on the carbene and the other by the
The stereochemistry of the double bond is preserved in the reaction as it is a concerted addition. If the alkene has a cis configuration, the two similar substituents on the double bond end up on the same side of the cyclopropyl ring in the product. If it is a trans alkene, the similar substituents on the double bond end up on opposite sides of the ring in the product.
Carbenes are generated in situ, typically by irradiating a mixture of the alkene and diazomethane with UV light or by treating a mixture of the alkene and haloform (trihalomethane) with a strong base like an alkoxide.
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Chapter 12 Solutions
Organic Chemistry: Principles and Mechanisms (Second Edition)
- Draw the predominant product(s) of the following reaction including stereochemistry when it is approprarrow_forwardIndane can undergo free-radical chlorination at any of the alkyl positions onthe aliphatic ring.Draw the possible dichlorinated products from this reaction.arrow_forwardPlease answer this Can you give examples to explain Addition reactions-general characteristics Benzene rings do not reactthi like alkenes Remember, the electrophile adds to the less substituted carbon, and the nucleophile to the more substituted carbon. Markovnikov’s Rule: The addition of a hydrogen halide to an alkene favors the product in which the proton adds to the alkene carbon that is initially bonded to the greater number of hydrogen atoms. Carbocation rearrangements- Methyl groups and hydride groups can migrate to make a more stable carbocation. A primary carbocation is less stable than a secondary carbocation, which is less stable than a tertiary carbocation. Addition of A Strong Bronsted Acid Hydrohalogenation HX addition to an alkene. Goes through a carbocation intermediate. The electrophile (H+) adds to the less substituted carbon, and the carbocation forms on the more substituted carbon. The nucleophile (X-) then adds to the more substituted carbocation.…arrow_forward
- Fill in the missing structure(s) for the reaction pathways shown below. Provideall starting material(s), reagent(s), or product(s). If more than one product can beformed, draw all major products. If more than one starting material or reagent ispossible, write all starting materials or reagents. Include stereochemistry in youranswer, if applicable, and draw all stereoisomers. Don't forget about resonance.arrow_forwardCurved arrows are used to illustrate the flow of electrons. Use the reaction conditions provided and follow the arrows to draw the reactant, intermediates, and product in this condensation reaction. Include all lone pairs and charges as appropriate. Ignore stereochemistry. Ignore inorganic byproducts. CH3ONA, CH3OH Select to Draw heat CH3ON a, CH3OH heatarrow_forwardHow many of the given alkenes will have the same acid-catalyzed hydration and oxymercutation/demercuration?arrow_forward
- Follow the arrows to predict the intermediate and product of this reaction. Include all lone pairs. Ignore stereochemistry. Ignore inorganic byproducts.arrow_forwardDraw the alkene that would react with the reagent given to account for the product formed. CH3 HCI CH3 CHCCH, ? + Či CH3 You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms. • In cases where there is more than one answer, just draw one.arrow_forwardRank the alkenes in order of decreasing heat of hydrogenation. A Highest heat of hydrogenation Lowest heat of hydrogenation Answer Bankarrow_forward
- Using Zaitsev's rule, choose the most stable alkene among the following. Draw out the structures of each of the options then select the correct answer. Recall that Zaitsev's Rule is about alkene stability. The trend for this is similar to the trend for carbocation stability. Either more or fewer groups on the alkene (and the carbocation) make it more stable. This question is wanting you to remember if it's more or fewer. A) 1,2-dimethylcyclohexene B) 1,6-dimethylcyclohexene C) cis-3,4-dimethylcyclohexene D) They are all of equal stability according to Zaitsev's rule. Provide the major dehydration product of the following reaction. Recall which of the four substitution and elimination reactions a dehydration is. Before you do your S# or EF mechanism, remember what heteroatoms do in the presence of an acid (aka-the-OH is a bad leaving group, but protonating it might turn it into a good one). Don't forget to apply the concept from the previous question. OH Ht Aarrow_forwardEach of these reaction produces ONE MAJOR PRODUCT. In each case, draw this product in the box provided, including appropriate stereochemistry when applicable. For multi-step reactions, just give the FINAL product, no intermediates.arrow_forwardSee image belowarrow_forward
Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning