Concept explainers
Many polycyclic
An arenium ion is an intermediate in this reaction, and the last step involves the dehydration of an alcohol. Propose a plausible mechanism for this example of the Bradsher reaction.
Want to see the full answer?
Check out a sample textbook solutionChapter 15 Solutions
Organic Chemistry
Additional Science Textbook Solutions
College Physics: A Strategic Approach (3rd Edition)
Human Biology: Concepts and Current Issues (8th Edition)
Microbiology with Diseases by Body System (5th Edition)
Applications and Investigations in Earth Science (9th Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
The Cosmic Perspective (8th Edition)
- Nonconjugated , -unsaturated ketones, such as 3-cyclohexenone, are in an acid-catalyzed equilibrium with their conjugated , -unsaturated isomers. Propose a mechanism for this isomerization.arrow_forwardTerpin, prepared commercially by the acid-catalyzed hydration of limonene, is used medicinally as an expectorant for coughs. (a) Propose a structural formula for terpin and a mechanism for its formation. (b) How many cis, trans isomers are possible for the structural formula you propose?arrow_forwardEnamines normally react with methyl iodide to give two products: one arising from alkylation at nitrogen and the second arising from alkylation at carbon. For example, Heating the mixture of C-alkylation and N-alkylation products gives only the product from C-alkylation. Propose a mechanism for this isomerization.arrow_forward
- A problem often encountered in the oxidation of primary alcohols to acids is that esters are sometimes produced as by-products. For example, oxidation of ethanol yields acetic acid and ethyl acetate: Propose a mechanism to account for the formation of ethyl acetate. Take into account the reversible reaction between aldehydes and alcohols:arrow_forwardAll rearrangements we have discussed so far have involved generation of an electron-deficient carbon followed by a 1,2-shift of an atom or a group of atoms from an adjacent atom to the electron-deficient carbon. Rearrangements by a 1,2-shift can also occur following the generation of an electron-deficient oxygen. Propose a mechanism for the acid-catalyzed rearrangement of cumene hydroperoxide to phenol and acetone.arrow_forwardA newer generation of antipsychotics, among them clozapine, are now used to treat the symptoms of schizophrenia. These drugs are more effective than earlier drugs in improving patient response in the areas of social withdrawal, apathy, memory, comprehension, and judgment. They also produce fewer side effects such as seizures and tardive dyskinesia (involuntary body movements). In the following synthesis of clozapine, Step 1 is an Ullmann coupling, a type of nucleophilic aromatic substitution that uses a copper catalyst. (a) Show how you might bring about formation of the amide in Step 2. (b) Propose a reagent for Step 3. (c) Propose a mechanism for Step 4. (d) Is clozapine chiral? If so, how many of the possible stereoisomers are formed in this synthesis?arrow_forward
- CH3 གོན་ནི། ཡོན་ Br₂, H₂C CH₂Br H3C CH3 H₂C CH3 Aldehydes and ketones can be halogenated at their a-position by reaction with Cl₂, Br2, or 12, under acidic conditions. Using Br₂ under acidic conditions, an intermediate enol is formed which adds bromine at the a-position. The reaction stops after the addition of one bromine because the electron-withdrawing halogen decreases the basicity of the carbonyl oxygen, making the protonation less favorable. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions :0: :OH н-он H-OH₂ H₂O H₂C. H3C. CH3 CH3 H3C CH3 H3C CH3 Σαarrow_forwardThe following reaction was performed as part of a research program sponsored by the National Institutes of Health to develop therapeutic agents for the treatment of cocaine addiction. Using what you have seen about the reactions of halogens with alkenes, propose a mechanism for this process.arrow_forwardAlcohols are acidic in nature. Therefore, a strong base can abstract the acidic hydrogen atom of the alcohol in a process known as deprotonation. The alcohol forms an alkoxide ion by losing the proton attached to the oxygen atom of the hydroxyl ( -OH) group. The alkoxide formed can act as a base or a nucleophile depending on the substrate and reaction conditions. However, not all bases can abstract the acidic proton of alcohols and not all alcohols easily lose the proton. Deprotonation depends on the strength of the base and the acidity of the alcohol. Strong bases, such as NaNH2, can easily abstract a proton from almost all alcohols. Likewise, more acidic alcohols lose a proton more easily. Determine which of the following reactions would undergo deprotonation based on the strength of the base and the acidity of the alcohol. Check all that apply. ► View Available Hint(s) CH3CH,OH + NH3 →CH,CH,O-NH CH3 CH3 H3C-C-H+NH3 → H3 C-C-H OH O-NH CH3CH2OH + NaNH, → CH3CH,O-Na* + NH3 CHC12 Cl₂…arrow_forward
- Ketones and aldehydes react with sodium acetylide (the sodium salt of acetylene) to give alcohols, as shown in the following example: R1 ОН 1. НС—с: Na* R2 R1 R2 2. Нзо" HC Draw the structure of the major reaction product when the following compound reacts with sodium acetylide, assuming that the reaction takes preferentially from the Si face of the carbonyl group. • Use the wedge/hash bond tools to indicate stereochemistry where it exists. • You do not have to explicitly draw H atoms. • If a group is achiral, do not use wedged or hashed bonds on it. CH3 CHarrow_forwardAn organic chemistry student combines sodium amide and an alkyne. The major ion product of that reaction is then combined with an aldehyde, followed by a work-up with pyridine. Which of the following functional groups will be in the major product? aldehyde ketone alkyne alcohol alkene Grignard reagent O amidearrow_forwardThe following substances can be prepared by a nucleophilic addition reaction between an aldehyde or ketoneand a nucleophile. Identify the reactants from which they were prepared. If the substance is an acetal, identifythe carbonyl compound and the alcohol; if it is an imine or enamine, identify the carbonyl compound and theamine. You do not have to consider stereochemistry. In cases where there is more than one answer, just giveone. Use Grignard reagents when an organometallic reagent is required. Draw the Grignard reagent as acovalent magnesium bromide.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning