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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 alkene that would react with the reagent given to account for the product formed. ? + H₂O H₂SO4 CH3 CH3CCH3 OH 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. Sn [F ChemDoodleⓇarrow_forwardA common alkene starting material is shown below. Predict the major product or missing reagent to complete each reaction. Use a dash or wedge bond to indicate stereochemistry, where applicable. Ignore inorganic byproducts.arrow_forwarda) How many monochlorination products can be obtained from the radical chlorination of methylcyclohexane? Disregard stereoisomers. b) Which product would be obtained in greatest yield? Briefly explain. c) How many monochlorination products would be obtained if all stereoisomers are included?arrow_forward
- For each of the following reaction, fill in the missing starting materials ,reaction conditions, or products. If more than one product is formed, draw only the major organic product. If no reaction occurs, write “no reaction.” Indicate appropriate stereochemistry only when necessary. If multiple steps are required, use numbers to indicate orderarrow_forwardWrite and the major product for each of the following reactions. Are these reactions stereospecific? Why, or why not? Are the reactions Stereoselective? Why or why not?arrow_forwardEach of these reactions 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_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_forwardIndane can undergo free-radical chlorination at any of the alkyl positions onthe aliphatic ring.Draw the possible dichlorinated products from this reaction.arrow_forwardDraw the products of the following reactions, indicating both regiochemistry and stereochemistry when appropriate. Use wedge and hash bonds ONLY when needed to show reaction stereochemistry. In cases where there is more than one answer, just draw one.arrow_forward
- Which alkene product would you expect to be the major product under kinetic conditions? Under thermodynamic conditions? The given pictures are the reactions in which we have to determine which alkene product we expect would be the major product under kinetic and thermodynamic conditions.arrow_forward• Same reagents as acid-catalyzed dehydration, except starting with a instead of an alcohol. • Same as the general mechanism hydrohalogenation, except with . Remember that EVERY acid-cat. mechanism begins with General Reaction: EXAMPLE: Provide H₂O H₂SO4 EXAMPLE: Provide the mechanism for the following addition reaction. H₂O H₂SO4 OH WH H₂O H₂SO4 as the nucleophile and ends with do PRACTICE: Provide the mechanism and predict the product of the following reaction. MAXOarrow_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_forward
Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning