How could you prepare benzyl phenyl ether from benzene and phenol? More than one step is

Name the following ethers: Equation Transcription: Text Transcription: CH3CH3 CH3CHOCHCH3 OCH2CH2CH3 OCH3 OCH3 CH3 CH3CHCH2OCH2CH3 H2C=CHCH2OCH=CH2

Why do you suppose only symmetrical ethers are prepared by the sulfuricacid-catalyzed dehydration procedure? What product(s) would you expect if ethanol and 1-propanol were allowed to react together? In what ratio would the products be formed if the two alcohols were of equal reactivity?

How would you prepare the following ethers using a Williamson synthesis? (a) Methyl propyl ether (b) Anisole (methyl phenyl ether) (c) Benzyl isopropyl ether (d) Ethyl 2,2-dimethylpropyl ether

How would you prepare ethyl phenyl ether? Use whichever method you think is more appropriate, Williamson synthesis or the alkoxymercuration reaction.

Review the mechanism of oxymercuration shown in Figure 8-3 on page 230, and then write the mechanism of the alkoxymercuration reaction of 1-methylcyclopentene with ethanol. Use curved arrows to show the electron flow in each step.

How would you prepare the following ethers? Use whichever method you think is more appropriate, Williamson synthesis or the alkoxymercuration reaction. (a) Butyl cyclohexyl ether (b) Benzyl ethyl ether \(\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{OCH}_{2} \mathrm{CH}_{3}\right)\) (c) sec-Butyl tert-butyl ether (d) Tetrahydrofuran Equation Transcription: Text Transcription: (C6H5CH2OCH2CH3)

Rank the following halides in order of their reactivity in Williamson synthesis: (a) Bromoethane, 2-bromopropane, bromobenzene (b) Chloroethane, bromoethane, 1-iodopropene

Predict the products of the following reaction: Equation Transcription: Text Transcription: CH3 CH3C-O-CH2CH2CH3 CH3 HBr

Predict the products of the following reactions: Equation Transcription: Text Transcription: CH3 HBr CH3 CH3CH2CH-O-CH2CH2CH3 HBr

Write the mechanism of the acid-induced cleavage of tert-butyl cyclohexyl ether to yield cyclohexanol and 2-methylpropene.

Why are HI and HBr more effective than HCl in cleaving ethers? (See Section 11-3.)

What product would you expect from Claisen rearrangement of 2-butenyl phenyl ether?

Reaction of cis-2-butene with m-chloroperoxybenzoic acid yields an epoxide different from that obtained by reaction of the trans isomer. Explain.

Predict the major product of the following reaction:

Predict the major product of each of the following reactions: Equation Transcription: Text Transcription: CH3 CH3

How would you prepare the following diols?

Predict the major product of the following reactions: Equation Transcription: Text Transcription: H2C CH3 CH2CH3 NaOH H2O18 H2C CH3 CH2CH3 H30+18 H3C CH2CH3 CH3 MgBr H3O+

15-Crown-5 and 12-crown-4 ethers complex \(\mathrm{Na}^{+} \text {and } \mathrm{Li}^{+}\), respectively. Make models of these crown ethers, and compare the sizes of the cavities. Equation Transcription: Text Transcription: Na+ and Li+

Name the following compounds: Equation Transcription: Text Transcription: CH3 CH3CH2CHSH CH3 CH3 CH3CCH2CHC2CHCH3 CH3 CH3 CH3CHSCH2CH3 SCH3 SCH3 SCH2CH3

2-Butene-1-thiol is one component of skunk spray. How would you synthesize this substance from methyl 2-butenoate? From 1,3-butadiene? Equation Transcription: Text Transcription: CH3CH=CHCOCH3 \longrightarrow CH3CH=CHCH2SH

The \({ }^{1} H N M R\) spectrum shown is that of a cyclic ether with the formula \(C_{4} H_{8} O\). Propose a structure. Equation Transcription: Text Transcription: { }^{1} H N M R C_{4} H_{8} O \delta

Give IUPAC names for the following compounds (reddish brown 5 Br; yellow 5 S):

Show the product, including stereochemistry, that would result from reaction of the following epoxide with HBr:

Show the product, including stereochemistry, of the following reaction: Equation Transcription: Text Transcription: CH3MgBr,ether H3O+

Treatment of the following alkene with a peroxyacid yields an epoxide different from that obtained by reaction with aqueous \(B r_{2}\) followed by base treatment. Propose structures for the two epoxides, and explain the result. Equation Transcription: Text Transcription: B r_{2}

Predict the product(s) and provide the mechanism for each reaction below. What does each mechanism have in common? Equation Transcription: Text Transcription: HBr OCH3 OCH2CH3 HBr CH3CH2CH2O

Predict the product(s) and provide the mechanism for each reaction below. What does each mechanism have in common? Equation Transcription: Text Transcription: HBr OC(CH3) HBr CH3CH2O

Predict the product(s) and provide the mechanism for each two-step process below. Equation Transcription: Text Transcription: NaOH CH3CH2I NaH CH3CH2CH2Br NaH CH3Br

The alkoxymercuration of alkenes involves the formation of an organomercury intermediate (I), which is reduced with NaBH4 to give an ether product. For each reaction below, predict the ether product and provide the mechanism formation. Equation Transcription: Text Transcription: Hg(CH3CO2)2 CH3OH NaBH4 Hg(CH3CO2)2 (CH3)2CHOH NaBH4 Hg(CF3CO2)2 CH3CH2OH NaBH4

Predict the product(s) and provide the mechanism for each reaction below. What do the mechanisms have in common? Equation Transcription: Text Transcription: CH3 CH3 CH3 CH3ONa CH3OH CH3 CH3MgBr H3O+ CH2CH3 HBr CH2CH2CH3 CH3NH2

Predict the product(s) and provide the mechanism for each reaction below. What do the mechanisms have in common? Equation Transcription: Text Transcription: CH2CH3 CH3 HCI CH3 HBr CH3 H3O+ CH3CH2 HCI

In the formation of the prepolymer used to make epoxy resins, a bisphenol reacts with epichlorohydrin in the presence of a base. Show the product and mechanism when two moles of phenol react with epichlorohydrin. Equation Transcription: Text Transcription: NaOH H_2O

Ethers undergo an acid-catalyzed cleavage reaction when treated with the Lewis acid \(B B r_{3}\) at room temperature. Propose a mechanism for the reaction. Equation Transcription: Text Transcription: BBr3 CH3 BBr3 H2O CH3Br

Treatment of 1,1-diphenyl-1,2-epoxyethane with aqueous acid yields diphenylacetaldehyde as the major product. Propose a mechanism for the reaction. Equation Transcription: Text Transcription: H3O+ PhCHCH

Fluoxetine, a heavily prescribed antidepressant marketed under the name Prozac, can be prepared by a route that begins with reaction between a phenol and an alkyl chloride. (a) The rate of the reaction depends on both phenol and alkyl halide. Is this an \(S_{N} 1\) or an \(S_{N} 2\) reaction? Show the mechanism. (b) The physiologically active enantiomer of luoxetine has (S) stereochemistry. Based on your answer in part (a), draw the structure of the alkyl chloride you would need, showing the correct Stereochemistry. Equation Transcription: Text Transcription: F3C CH3 CH3 F3C CH3 CH3 F3C CH3 SN1 SN2

When 2-methyl-2,5-pentanediol is treated with sulfuric acid, dehydration occurs and 2,2-dimethyltetrahydrofuran is formed. Suggest a mechanism for this reaction. Which of the two oxygen atoms is most likely to be eliminated, and why? Equation Transcription: Text Transcription: CH3 CH3

Methyl aryl ethers, such as anisole, are cleaved to iodomethane and a phenoxide ion by treatment with LiI in hot DMF. Propose a mechanism for this reaction.

The herbicide aciluorfen can be prepared by a route that begins with reaction between a phenol and an aryl luoride. Propose a mechanism. Equation Transcription: Text Transcription: NO2 CO2CH3 F3C NO2 CO2CH3 F3C NO2 CO2CH3 F3C

Aldehydes and ketones undergo acid-catalyzed reaction with alcohols to yield hemiacetals, compounds that have one alcohol-like oxygen and one ether-like oxygen bonded to the same carbon. Further reaction of a hemiacetal with alcohol then yields an acetal, a compound that has two ether-like oxygens bonded to the same carbon. (a) Show the structures of the hemiacetal and acetal you would obtain by reaction of cyclohexanone with ethanol. (b) Propose a mechanism for the conversion of a hemiacetal into an acetal. Equation Transcription: Text Transcription: H+ H2O

Propose a mechanism to account for the following transformation. What two kinds of reactions are occurring? Equation Transcription: Text Transcription: H3C CH3 CH3 H3C

Draw structures corresponding to the following IUPAC names: (a) Ethyl 1-ethylpropyl ether (b) Di(p-chlorophenyl) ether (c) 3,4-Dimethoxybenzoic acid (d) Cyclopentyloxycyclohexane (e) 4-Allyl-2-methoxyphenol (eugenol; from oil of cloves)

Give IUPAC names for the following structures: Equation Transcription: Text Transcription: OCH3 OCH3 CH3 CH3 CH3CH NO2 CH3 CH3 CH3CH2CHCHCHSCHCH3 CH3 CH3 OCH3 CH3CCH3 OCH3 SCH3 SCH3

How would you prepare the following ethers? Equation Transcription: Text Transcription: CH2CH3 CHCH3 CH3 H3C CH3 CH3 CH3 CH3 OCH3 OCH3 OCH3

How would you prepare the following compounds from 1-phenylethanol? (a) Methyl 1-phenylethyl ether (b) Phenylepoxyethane (c) tert-Butyl 1-phenylethyl ether (d) 1-Phenylethanethiol

tert-Butyl ethers can be prepared by the reaction of an alcohol with 2-methylpropene in the presence of an acid catalyst. Propose a mechanism for this reaction.

Treatment of trans-2-chlorocyclohexanol with NaOH yields 1,2-epoxycyclohexane, but reaction of the cis isomer under the same conditions yields cyclohexanone. Propose mechanisms for both reactions, and explain why the different results are obtained. Equation Transcription: Text Transcription: NaOH H2O NaOH H2O

Predict the products of the following ether cleavage reactions: Equation Transcription: Text Transcription: CH2CH3 H2O H3C CH3 CH3 H2C=CH=0=CH2CH3 H2O CH3 CH3CCH2-O-CH2CH3 CH3 H2O

How would you carry out the following transformations? More than one step may be required. OCH2CH3 (a) ? ? OCH3 H3C (b) ? H H H H3C Br H H3C H3C CH3 (c) CH3CH2CH2CH2C CH CH3CH2CH2CH2CH2CH2OCH3 (d) C H3C H3C CH3 C OH OH H H H ? CH3CH2CH2CH2C CH CH3CH2CH2CH2CHCH3 OCH3

What product would you expect from cleavage of tetrahydrofuran with HI?

Write the mechanism of the hydrolysis of cis-5,6-epoxydecane by reaction with aqueous acid. What is the stereochemistry of the product, assuming normal backside \(S_{N}{ }^{2}\) attack? Equation Transcription: Text Transcription: S_{N}{ }^{2}

What is the stereochemistry of the product from acid-catalyzed hydrolysis of trans-5,6-epoxydecane? How does the product differ from that formed in Problem 18-47?

Acid-catalyzed hydrolysis of a 1,2-epoxycyclohexane produces a transdiaxial 1,2-diol. What product would you expect to obtain from acidic hydrolysis of cis-3-tert-butyl-1,2-epoxycyclohexane? (Recall that the bulky tert-butyl group locks the cyclohexane ring into a speciic conformation.)

Imagine that you have treated (2R,3R)-2,3-epoxy-3-methylpentane with aqueous acid to carry out a ring-opening reaction. (a) Draw the epoxide, showing stereochemistry. (b) Draw and name the product, showing stereochemistry. (c) Is the product chiral? Explain. (d) Is the product optically active? Explain. Equation Transcription: Text Transcription: CH3C-CCH2CH3 CH3

Epoxides are reduced by treatment with lithium aluminum hydride to yield alcohols. Propose a mechanism for this reaction. Equation Transcription: Text Transcription: LiAlH4,ether H3O+

Show the structure and stereochemistry of the alcohol that would result if 1,2-epoxycyclohexane were reduced with lithium aluminum deuteride, \(\mathrm{LiAlD}_{4}\) (Problem 18-51). Equation Transcription: Text Transcription: LiAlD_4

The red fox (Vulpes vulpes) uses a chemical communication system based on scent marks in urine. One component of fox urine is a sulide whose mass spectrum has \(M^{+}=116 . I R\) spectroscopy shows an intense band at \(890 \mathrm{~cm}^{-1}, \text { and }^{1} H N M R\) spectroscopy reveals the following peaks: \(1.74 \delta\) (3 H, singlet); \(2.11 \delta\) (3 H, singlet); \(2.27 \delta\) (2 H, triplet, J 5 4.2 Hz); \(2.57 \delta\) (2 H, triplet, J 5 4.2 Hz); \(4.73 \delta\) (2 H, broad) Propose a structure consistent with these data. [Note: \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{~S}\) absorbs at \(2.1 \delta\).] Equation Transcription: Text Transcription: M^{+}=116 . I R 890 \mathrm{~cm}^{-1}, \text { and }^{1} H N M R 1.74 \delta 2.11 \delta 2.27 \delta 2.57 \delta 4.73 \delta \left(\mathrm{CH}_{3}\right)_{2} \mathrm{~S} 2.1 \delta

Anethole, \(C_{10} H_{12} O\), a major constituent of the oil of anise, has the \({ }^{1} H N M R\) spectrum shown. On oxidation with \(N a_{2} C r_{2} O_{7}\), anethole yields p-methoxybenzoic acid. What is the structure of anethole? Assign all peaks in the NMR spectrum, and account for the observed splitting patterns. Equation Transcription: Text Transcription: C_{10} H_{12} O { }^{1} H N M R N a_{2} C r_{2} O_{7} \delta

Propose structures for compounds that have the following \({ }^{1} H N M R\) spectra: (a) \(C_{5} H_{12} S\) (An ] SH proton absorbs near \(1.6 \delta\).) (b) \(C_{9} H_{11} B r O\) (c) \(\mathrm{C}_{5} \mathrm{H}_{12} \mathrm{O}_{2}\) Equation Transcription: Text Transcription: { }^{1} H N M R C_{5} H_{12} S 1.6 \delta \delta C_{9} H_{11} B r O \delta \mathrm{C}_{5} \mathrm{H}_{12} \mathrm{O}_{2} \delta

Predict the products of the following reactions: Equation Transcription: Text Transcription: CH3 OCH2CHCH3 HBr CH3 CH3CHCH2CH2CH2Br (NH2)2=S NaOH,H2O Br2 SCH2CH3 H2O2,H2O

How would you synthesize anethole (Problem 18-54) from phenol?

How could you prepare benzyl phenyl ether from benzene and phenol? More than one step is required.

Meerwein’s reagent, triethyloxonium tetraluoroborate, is a powerful ethylating agent that converts alcohols into ethyl ethers at neutral pH. Show the reaction of Meerwein’s reagent with cyclohexanol, and account for the fact that trialkyloxonium salts are much more reactive alkylating agents than alkyl iodides. \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{3} \mathrm{O}^{+} \mathrm{BF}_{4}-\) Meerwein’s reagent Equation Transcription: Text Transcription: \left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{3} \mathrm{O}^{+} \mathrm{BF}_{4}-

Safrole, a substance isolated from oil of sassafras, is used as a perfumery agent. Propose a synthesis of safrole from catechol (1,2-benzenediol). Equation Transcription: Text Transcription: CH2CH=CH2

Grignard reagents react with oxetane, a four-membered cyclic ether, to yield primary alcohols, but the reaction is much slower than the corresponding reaction with ethylene oxide. Suggest a reason for the difference in reactivity between oxetane and ethylene oxide. Equation Transcription: Text Transcription: RMgX H3O+ RCH2CH2CH2OH

The Zeisel method is an old analytical procedure for determining the number of methoxyl groups in a compound. A weighed amount of the compound is heated with concentrated HI, ether cleavage occurs, and the iodomethane product is distilled off and passed into an alcohol solution of \(\mathrm{AgNO}_{3}\), where it reacts to form a precipitate of silver iodide. The AgI is then collected and weighed, and the percentage of methoxyl groups in the sample is thereby determined. For example, 1.06 g of vanillin, the material responsible for the characteristic odor of vanilla, yields 1.60 g of AgI. If vanillin has a molecular weight of 152, how many methoxyl groups does it contain? Equation Transcription: Text Transcription: AgNO_3

Disparlure, \(\mathrm{C}_{19} \mathrm{H}_{38} \mathrm{O}\), is a sex attractant released by the female gypsy moth, Lymantria dispar. The \({ }^{1} \mathrm{HNMR}\) spectrum of disparlure shows a large absorption in the alkane region, \(1 \text { to } 2 \delta\), and a triplet at \(2.8 \delta\). Treatment of disparlure, irst with aqueous acid and then with \(\mathrm{KMnO}_{4}\), yields two carboxylic acids identiied as undecanoic acid and 6-methylheptanoic acid. (\(\mathrm{KMnO}_{4}\) cleaves 1,2-diols to yield carboxylic acids.) Neglecting stereochemistry, propose a structure for dis parlure. The actual compound is a chiral molecule with 7R,8S stereochemistry. Draw disparlure, showing the correct stereochemistry. Equation Transcription: Text Transcription: \mathrm{C}_{19} \mathrm{H}_{38} \mathrm{O} { }^{1} \mathrm{HNMR} 1 \text { to } 2 \delta 2.8 \delta \mathrm{KMnO}_{4} \mathrm{KMnO}_{4}

How would you synthesize racemic disparlure (Problem 18-63) from compounds having ten or fewer carbons?

How would you prepare o-hydroxyphenylacetaldehyde from phenol? More than one step is required. Equation Transcription: Text Transcription: OH CH2CHO

Identify the reagents a–e in the following scheme: Equation Transcription: Text Transcription: OH CH3 OCH3 OCH3 CH3 CH3 CH3 OH OH

Propose structures for compounds that have the following \({ }^{1} H N M R\) spectra: (a) \(C_{4} H_{10} O_{2}\) (b) \(C_{9} H_{10} O\) Equation Transcription: Text Transcription: { }^{1} H N M R C_{4} H_{10} O_{2} \delta C_{9} H_{10} O \delta

We saw in Section 17-4 that ketones react with \(\mathrm{NaBH}_{4}\) to yield alcohols. We’ll also see in Section 22-3 that ketones react with \(\mathrm{Br}_{2}\) to yield \(\alpha\)-bromo ketones. Perhaps surprisingly, treatment with \(\mathrm{NaBH}_{4}\) of the \(\alpha\)-bromo ketone from acetophenone yields an epoxide rather than a bromo alcohol. Show the structure of the epoxide, and explain its formation. Equation Transcription: Text Transcription: NaBH4 Br2 \alpha NaBH4 \alpha CH3 Br2 CH2Br NaBH4

In nature, the enzyme chorismate mutase catalyzes a Claisen rearrangement of chorismate that involves both the terminal double bond and the double bond with the highlighted carbon. What is the structure of prephenate, the biological precursor to the amino acids phenylalanine and tyrosine? Equation Transcription: Text Transcription: CO2- HO CO2-

Predict the product(s) if the starting materials below underwent a Claisen rearrangement. Draw arrows to illustrate the rearrangement of electrons. Equation Transcription: Text Transcription: CH3 CH2 D2C CH3 H2C CH3

Judging from the following electrostatic potential maps, which kind of carbonyl compound has the more electrophilic carbonyl carbon atom, a ketone or an acid chloride? Which has the more nucleophilic carbonyl oxygen atom? Explain.

Predict the product formed by nucleophilic addition of cyanide ion \(\left(C N^{-}\right)\) to the carbonyl group of acetone, followed by protonation to give an alcohol: Equation Transcription: Text Transcription: (CN-) H3C CH3 CN- H3O+

Identify each of the following reactions as a nucleophilic addition, nucleophilicacyl substitution, an a substitution, or a carbonyl condensation: Equation Transcription: Text Transcription: H3C NH3 H3C NH2 H3C NH2OH H3C NaOH