Chapter 10:Alcohols, Phenols and Ethers §10.1.Alcohols Alcohols are organic compounds containing hydroxyl (-OH) groups. They are some of the most common and useful compounds in nature, in industry, and around the house. 1. Classifications, Nomenclature and Structure of Alcohols 1) Classification of Alcohols primary alcohol secondary alcohol tertiary alcohol unitary alcohol duality alcohol ternary alcohol 2) Nomenclature of Alcohols Common Names: OH H3C OH methyl alcohol H3CH2CH2C OH n-propyl alcohol H3C CH isopropyl alcohol OH H3CH2CH2CH2C OH H C 3 n-butyl alcohol allyl alcohol and CH H C H2C CH3 sec-butyl alcohol C CH3 t-butyl alcohol OH allyl alcohol CH3 CH3 CH2CH3 H3C H2 C OH H3C CH H2 C isobutyl alcohol isopropyl alcohol IUPAC Names: The formal rules are summarized according three steps: 1. Name the longest carbon chain bearing the—OH group. 2. Number the longest carbon chain starting at the end nearest the hydroxyl group. 3. Name all the substituents and give numbers, as you would for and an alkane or an alkene. OH CH3 OH H3C 4 3 C CH 2 H2 C Br 1 CH3 1- bromo-3,3-dimethylbutan-2-ol 3,3-二甲基- 1-溴-2-丁醇 . OH OH OH H3C CH OH CH2OH OH propane-1,2-diol 1-cyclohexylbutane-1,3-diol H2C CH2 H2C OH OH IUPAC name: ethane-1,2-diol common name: ethylene glycol H C trans-cyclopentane-1,2-diol OH CH3 OH OH OH propane-1,2-diol propylene glycol cis-cyclohexane-1,2-diol cis-cyclohexene glycol 3)Structure of Alcohols H 109° C 143ppm O u=5.70x10-30 H H H 2.Physical Properties of Alcohols Boiling Points Solubility Properties 3.Spectroscopy Infrared Spectroscopy O-H 3300cm-1 C-O 1000-1200cm-1 Proton NMR Spectroscopy O-H δ:0.5-4.5 ppm (solvent, concentration, temperature) RCH2OH δ:3.4-4.0 ppm 4. Reactions of Alcohols Alcohols are important organic compounds because the hydroxyl group is easily converted to almost any other functional group. In Chapter 10, we studied reactions that form alcohols. In this chapter, we will study reactions of hydroxyl group. 1) Reaction with lively metals form alkoxides: R Na + OH CH3CH2OH R _1 2 H2 + CH3CH2 O + Na Na + O + Na _1 2 H2 + The reactivity of alcohols: methyl>1°>2°>3° 2) Reactions of Alcohols with Hydrohalic Acids R OH + HX R Example: CH3(CH2)2 CH2OH NaBr,H2SO4 + X H2O CH3(CH2)2 CH2Br 1-bromobutane(99%) 1-butanol Mechanism: SN1 or SN2 H R O H + H R poor leaving group X- + O H good leaving group The reactivity: tertiary >secondary >primary HI > HBr > HCl >> HF Lucas reagents: SN1 or SN2 R X Concentrated HCl and ZnCl2 distinguish the structure(1°,2°,3°)of the alcohol. primary alcohol very fast secondary alcohol slow tertiary alcohol no reaction (r.t.) Rearrangement Meerwein rearrangement The pinacol Rearrangement H3C CH3 CH3 C C OH OH CH3 CH3 pinacol (2,3-dimethyl-2,3-butanediol ) Mechanism: H2SO4 100℃ H3C C C O CH3 CH3 pinacolone ( 3,3-dimethyl-2-butanone) + H2O Step 1:Protonation of a hydroxyl group Step 2: Loss of water gives a carbocation CH3CH3 CH3CH3 H3C C C CH3 + + H H3C C C CH3 CH3 H3C C HO OH2 HO OH CH3 + H2O C CH3 HO Step 3: Meth yl migration forms a resonance-stabilized carbocation CH3 H3C H C O ~CH3 (methyl migration) CH3 C CH3 CH3 H3C H C O C CH3 CH3 H3C C C CH3 H O OH CH3 2 resonance-stabilized carbocation Step 4: Deprotonation gives the product. CH3 H3C C O C CH3 CH3 H3C C O CH3 H2O H resonance-stabilized carbocation H C CH3 CH3 H3C OH2 C O C CH3 + OH2 pinacolone 3) Reations of alcohols with phosphorus halides 3ROH + PX3 3RX + P(OH)3 ROH + PCl5 RCl + POCl3 + HCl RCl + SO2 + HCl ROH + SOCl2 4) Esterification of Alcohols O O + R O H alcohol + H O C acid R' H R O C ester R' + H O H H3O+ H2SO4 (CH3)2CHOH + CH3COOH isopropyl alcohol acetic acid (CH3)2CHOOCCH3 + H2O isopropyl acetate 5)Esters of inorganic acid(nitric acid, sulfuric acid, phosphoric acid) Tosylate esters: para-toluenesulfonic acid and alcohols. O ROH + HO O S CH3 O para-toluenesulfonic acid (TsOH) alcohol O R S CH3 + H2 O O para-toluenesulfonate ester (ROTs) A sulfate ester : O OH O O S CH3OH OH H3C O sulfuric acid O S O methyl sulfate CH3OH OH H3C O + H2O S CH3 O + H2O O dimethyl sulfate Nitrate esters are formed from alcohols and nitric acid. O R O + H H alcohol O O N nitric acid R O O + H2O N O alkyl nitrite eater The best known nitrate ester is“nitroglycerine”: the reaction of glycerol(1, 2,3-propanetriol) with three molecules of nitric acid. H2C O H HC O H H2C O H + 3 HO glycerol (glycerine) NO2 nitric acid H2C O NO2 HC O NO2 H2C O NO2 + 3H2O glyceryl trinitrate (nitroglycerine) Alkyl phosphates are composed of 1 mole of phosphoric acid combined with 3 moles of an alcohol. For example, methanol forms three phosphate esters. HO H CO 3 3CH3OH + HO P O HO 6) Dehydration Reactions of Alcohols H3CO H3CO P O + 3H2O (1) Formation of Alkenes Mechanism:acid-catalyzed Dehydration of an alcohol H H OH C C H+ H O C C H H C H2O C C C + H3O+ We can summarize the dehydration and give guidelines for predicting the products: 1). Dehydration usually goes by the E1 mechanism. Rearrangements may occur to form more stable carbonations. 2). Dehydration works best with tertiary alcohols and almost as well with secondary alcohols. Rearrangements and poor yields are common with primary alcohols. 3). (Saytzeff rule) if two or more alkenes might be formed by deprotonation of the carbonations, the most highly substituted alkene usually predominates. (2)Bimolecular Dehydration to form Ethers I H H3C CH3 H SN2 CH3CH2 O C O CH3CH2 O C O H H H H H H H H nucleophilic electrophilic protonated ether water Substitution to give the ether, a bimolecular dehydration H2SO4 , 140℃ 2CH3CH2OH CH3CH2 O CH2CH3 ethanol diethyl ether Elimination to give the alkene, a unimolecular dehydration H2SO4 , 180℃ CH3CH2OH + H2O H2C CH2 ethanol ethylene CH3 CH3CH2 O C H H + H3O+ diethyl ether + H2O 7) Oxidation-reduction reaction Primary and secondary alcohols are easily oxidized by a variety of reagents, including chromium reagents, permanganate, nitric acid, and even household bleach(NaOCl, sodium hypochlorite). H O OH Na2Cr2O7 H2SO4 cyclohexanol cyclohexanone (90%) OH R C O [O] H primary alcohol R O C H [O] R C acid aldehyde OH Oppenauer Oxidaxion A better reagent for the limited oxidation of primary alcohols to aldehydes is pyridinium chlorochromate(PCC), a complex of chromium trioxide with pyridine and HCl. OH R C O CrO3.pyridine.HCl(PCC) H R CH2Cl2 H primary alcohol Example: H aldehyde + H3C(H2C)3 C CH2OH 1-heptanol 7) Reaction of polylol O - pyH CrO3Cl (PCC) CH2Cl2 H3C(H2C)3 C heptanal 78% H 5. Synthesis of Alcohols One of the reasons alcohols are important synthetic intermediates is that they can be synthesized directly from a wide variety of other functional groups. We have examined the conversion of alky halides to alcohols by substitution and the conversion of alkenes to alcohols by hydration, hydroboration, and hydroxylation. These reactions are summarized below: 1) Nucleophilic substitution on an alkyl halide R R C HO X HO H H R X HO H H transition state H X H Example: H Br HO KOH H C C H3C H3C CH2CH3 (s)-2- bromobutane CH2CH3 (R)-2-butanol,100% inverted confi guration 2) synthesis of alcohols from alkenes 1). Acid-catalyzed hydration C + C H+ H2O C C H OH 2).Oxymercuration-demercuration C + Hg(OAc)2 C H2O C (AcO)Hg C NaBH4 OH C C H OH Example: H3C CH3 C H C Hg(OAc)2 H2O CH3 3).Hydrobortion-oxidation H CH3 OH C C (AcO)Hg CH3 CH3 NaBH4 H CH3 OH C C H CH3 CH3 C (1)BH3.THF (2)H2O2,NaOH C C C H OH Example: CH3 CH3 CH3 H H H2O2,NaOH BH3.THF OH BH2 H H H 1-methylcyclopentene trans-2-methylcyclopentanol (85%) 4)Hydroxylation: synthesis of 1,2-diols from alkenes C OsO4,H2O2 C or KMnO4,OH(cold,dilute) C C OH OH syn hydroxylation Example: H H3CH2C CH2CH3 O H O KMnO4 H H CH2CH3 O- O CH2CH3 H3CH2C H OH OHH2O = H H3CH2C H OH H OH OH H3CH2C cis-3-hexaene CH2CH3 meso-3,4-hexanediol (60%) OH C C RCOOOH, H3O+ C C OH anti hydroxylation Example: H H3CH2C CH2CH3 HCO3H H O H H CH2CH3 cis-3-hexaene H3CH2C CH2CH3 H3CH2C H OH H3O+ = HO CH2CH3 H HO OH H H ( )-3,4-hexanediol (70%) CH2CH3 3) Synthesis of alcohols from carbonyl compounds (1) Addition of organometallic reagents to carbonyl compounds Grignard and organolithium reagents are strong nucleophiles and strong bases. Key mechanism: Grignard reactions First reaction: the Grignard reagent attacks a carbonyl compound to form an alkoxide salt. δ δ R MgX + C O R ether C O - + MgX magnesium alkoxide salt Second reaction: after the first reaction is complete, water or dilute acid is added to protonate the alkoxide. H R C O - + O H MgX R magnesium alkoxide salt O H + XMgOH alcohol the primary alcohol: H H CH3CH2CH2CH2 MgBr + C (1) ether solvent (2)H3O+ O H butylmagnesium bromode formaldehyde CH3CH2CH2CH2 C 1-pentanol (92%) H the secondary alcohol: CH3 H3C CH3CH2 MgBr + C O (1)ether solvent (2)H3O+ CH3CH2 C H OH H acetaldehyde 2-butanol (85%) the tertiary alcohol:. CH2CH2CH3 H3CH2CH2C CH3CH2 MgBr + C H3C 2-pentanone reaction with epoxides: Example: O (1)ether solvent (2)H3O+ CH3CH2 C OH CH3 3-methyl-3-hexanol (90%) OH O O H3C(H2C)3 MgX H2C CH2 H2C ether - + CH2 C4H9 butylmagnesium bromide OH MgX H3O+ H2C CH2 C4H9 1-hexanol (61%) ethylene oxide (2)Catalytic Hydrogenation of Ketones and Aldehydes O OH + H2 C Raney Ni CH3 H2C H C H2 C C CH3 CH CH3 O + 2H2 C Raney Ni H3C H2 C H C CH2OH CH3 2,2-dimethyl-4-pentenal 2,2-dimethyl-4-pentenol (94%) CH3 NaBH4 (for comparison) H2 C H2C H C H2 C C CH3 2,2-dimethylpent-4-en-1-ol 6. Some important Alcohols (Self-study) CH2OH §2. Phenols 1. Classifification, Nomenclature and Structure of Phenols O OH N OH OH O Br H3CH2C IUPAC: 2-bromophenol common name: ortho-bromophenol IUPAC: 2-methylphenol common name: ortho-cresol 3-nitrophenol meta-nitrophenol OH OH CH3 OH benzene-1,2-diol catechol 4-ethylphenol para-ethylphenol OH OH HO OH benzene-1,3-diol resorcinol benzene-1,4-diol hydr oquinone 2. Physical Properties of Phenols IR: O-H ν=3600cm-1 1 HNMR chemical shifts :δO-H = 4.5 - 8.0 in the 1HNMR spectrum. 3.Reactions of Phenols Much of the chemistry of phenols is like that of aliphatic alcohols. For example, phenols can be acylated to give esters, and phenoxide ions can serve as nucleophiles in the Williamson ether synthesis. Formation of phenoxide ions is particularly easy because phenols are more acidic than water, aqueous sodium hydroxide deprotonates phenols to give phenoxide ions. All the alcohol-like reactions involve breaking of the phenolic O-H bond. This is a common way for phenols to react. It is far more difficult to break the C-O bond of a phenol, however. Most alcohol reactions in which the C-O bond breaks are not possible with phenols. For example, phenols do not undergo acidcatalyzed elimination or SN2 back-side attack. Phenols also undergo reactions that are not possible with aliphatic alcohols. Let’s consider some reactions that are peculiar to phenols. 1) Acidity of Phenols carbolic acid: sodium or potassium metal. ONa OH + NaOH + H2O 2) Oxidation of phenols to quinones OH O N a 2 C r2 O 7 H 2S O 4 CH m -cres o l CH 3 3 O 2 -m eth yl-1 ,4 -b e n zo q u in o n e 2.3.3. Eletrophilic Aromatic Substitution of phenols Phenols are highly reactive substrates for elevtrophilic aromtic substitution because the nonbonding electrons of the hydroxyl group stabilize the sigma complex formed by attack at the ortho or para position (Section 17-6B). Therefore, the hydroxyl group is strongly activating and ortho, para-directing. Phenols are excellent substrates for halogention, nitration, sulfonation, and Friedel-Crafts reactions. Becaues they are highly reactive, phenols are usually alkylated or acylated using relatively weak Friedel-Crafts catalysts (such as HF) to avoid overalkylation or overacylation. OH OH OH OH + H3C CH CH( CH3)2 CH3 HF + CH(CH3)2 2.4. Preparation of Phenols 2.4.1. Incorporation Phenol groups can be incorporated into an aromatic ring by sulfonation of the aromatic rings followed by melting the product with sodium hydroxide to convert the sulfonic acid group to a phenol. The reaction conditions are harsh and only alkyl-substituted phenols can be prepared by this method. SO3H OH SO3 H2SO4 1) NaOH 2) H3O+ CH3 CH3 CH3 A more general method of synthesizing phenols is to hydrolyze a diazonium salt, prepared from an aniline group (NH2) NH2 NO2 H2NO3 Sn HCl H2SO4 OH N2HSO4 HNO2 H2SO4 H3O+ 2.4.2. Functional group transformation Various functional groups can be converted to phenols. Sulfonic acids and amino groups have already been mentioned. Phenol esters can be hydrolyzed (a). Aryl ethers can be cleaved (b). The bond between the alkyl group and oxygen is specifically cleaved since the Ar-OH bond is too strong to be cleaved. O R C a) H3O+ or NaOH OH b) Conc. HX heat O HO2C-R 2.5.Some important Phenols (Self-study) X-R O R §3. Ethers 3.1. Nomenclature ,Structure and Spectroscopy of Ethers Ethers are compounds of formula R-O-Rˊ,where R and Rˊmay be alkyl groups or aryl(benzene ring)groups. Like alcohols, ethers are related to water, with alkyl groups replacing the hydrogen atoms. In an alcohol, one hydrogen atom of water is replaced by an alkyl group. In an ether, both hydrogens are replaced by alkyl groups. The two alkyl groups are the same in a symmetrical ether and different in an unsymmetrical ether. H Examples of H3CH2C O H R O water ethers: O H R alcohol CH2CH3 O O R' ether CH3 O diethyl ether (a symmetrical ether) methyl phenyl ether (an unsymmetrical ether) tetrahydrofuran (a symmetrical,cyclic ether) Common names of ethers are formed by naming the two alkyl groups on oxygen and adding the word ether. Under the current system, the old system, which named the groups in order of increasing complexity. For example, if one of the alkyl groups is methyl and the other is t-butyl, the current common name should be “t-butyl methyl ether”, but most chemists use the older common name, “methyl t-butyl ether”(or MTBE). If both groups are methyl, the name is “dimethyl ether”. If just one alkyl group is described in the name, it implies the ether is symmetrical, as in “ethyl ether”. IUPAC names use the more complex group as the root name, and the rest of the ether as an alkoxy group. For example, cyclohexyl methyl ether is named merhoxycyclohexane. This systematic nomenclature is often the only clear way to name complex ethers. OCH3 H3C O IUPAC name: methoxyethane common name: ethyl methyl ether H3C H2 C Cl CH2CH3 methyoxylbenzene ethyl phenyl ether, anisole O CH3 chloromethoxymethane chloromethyl methyl ether CH3 Cl H H OCH2CH3 IUPAC name: 3-ethoxy-1,1'-dimethylcyclohexane OCH3 H H2C OH H2C O CH2CH3 2-ethoxyethanol trans-1-chloro-2-methoxycyclobutane Cyclic ethers are our first examples of heterocyclic compounds, containing a ring in which a ring atom is an element other than carbon. This atom, called the heteroatom, is numbered l in numbering the ring atoms. Heterocyalic ethers are an especially important and useful class of ethers. Infrared spectroscopy of ethers: Infrared spectra do not show obvious or reliable absorptions for ethers. Most ethers give a moderate to strong C-O stretch around 1000 to 2000cm-1(in the fingerprint region), but many compounds other than ethers give similar absorptions. Nevertheless, the IR spetrum can be useful because it shows the absence of carbonyl(C=O) groups. If the molecular formula contains an oxygen atom, the lack of carbonyl or hydroxyl absorptions in the IR suggests ether. NMR spectroscopy of ethers In the 13CNMR spectrum, a carbon atom bonded to oxygen generally absorbs between δ 65 and δ 90.Protons on carbon atoms bonded to oxygen usually absorb at chemical shifts betweenδ3.5and δ4 in the 1HNMR. spectrum Both alcohols and ethers have resonances in this range. 3.2. Physical properties of Ether Like water, ethers have a bent structure, with an sp3 hybrid oxygen atom giving a nearly tetrahedral bond angle. In water, the bulk of the alkyl groups enlarges the H-O-H bond angle to 104.5゜, but in a typical ether, the bulk of the alkyl groups enlarges the bond angle.. Although ethers lack the polar hydroxyl group of alcohols, they are still strongly polar compounds. The dipole moment of ether is vector sum of two polar C-O bonds, with a substantial contribution the two lone pairs of electrons. Table Table 14-1 Comparison of the Boiling points of Ethers, Alkanes, and Alcohols of similar Molecular Weights Compound Formula MW Dipole bp(℃) Moment(D) 18 100 1.9 water H2O ethanol CH3CH2-OH 46 78 1.7 dimethyl ether CH3-O-CH3 46 -25 1.3 propane CH3CH2CH3 44 -42 0.1 n-butanol CH3CH2CH2CH2-OH 74 118 1.7 72 66 1.6 tetrahydrofuran O diethyl ether CH3CH2-O-CH2CH3 74 35 1.2 pentane CH3CH2CH2CH2CH3 72 36 0.1 Note: The alcohols are hydrogen bonded, giving them much higher boiling points. The ethers have boiling points that are closer to those of alkanes with similar molecular weights. compares the dipole moments of dimethyl ether, diethyl ether, and tetrahydrofuran (THF) with those of alkanes and alcohols of similar molecular weights. An ether such as THF provides a strongly polar solvent without the reactivity of a hydroxyl group. Boiling points of Ethers; Hydrogen Bonding Table 14-1 compares the boiling points of several ethers, alcohols, and alkanes. Notice that the boiling points of dimethyl ether and diethyl ether are nearly 100℃ lower than those of alcohols having similar molecular weights. This large difference results mostly from hydrogen bonding in the alcohols. Pure ethers cannot engage in hydrogen bonding because they have no O-H groups. Ethers do have large dipole moments, resulting in dipole-dipole attractions, but these attractions appear to have relatively little effect on their boiling points. Although pure ethers have on hydroxyl groups to engage in hydrogen bonding, they can hydrogen bond with other compounds that do have O-H or N-H groups. Figure 14-2 shows that a hydrogen bond requires both a hydrogen bond donor and a hydrogen. TABLE14-2 physical properties of some Representative Ethers Name Structure mp(゜C) bp(゜C) eimethyl ether CH3-O-CH3 -140 -25 ethyl methyl ether CH3CH2-O-CH3 8 diethyl ether CH3CH2-O-CH2CH3 -116 35 di-n-propyl ether CH3CH2CH2-O-CH2CH2CH2 -122 91 diisopropyl ether (CH3)2CH-O-CH(CH3)2 -86 68 1,2-dimethoxyethane CH3-O-CH2CH2-O-CH3 -58 83 (DME) -37 154 Methyl phenyl ether H3C O (anisole) 27 259 diphenyl ether O furan Density(g/ml) 0.66 0.72 0.71 0.74 0.86 0.99 1.07 0.94 -86 32 0.89 -108 65 1.03 11 101 O tetrahydrofuran (THF) 1,4-dioxane O O O Bond acceptor. The donor is the molecule with an O-H or N-H group. The acceptor is the molecule whose lone pair of electrons forms a weak partial bond to the hydrogen atom provided by the donor. An ether molecule has the lone pair to form a hydrogen bond with an alcohol (or other hydrogen bond donor), but it cannot form a hydrogen bond with another ether more volatile than alcohols having similar molecular weights. Table 14-2 lists the physical properties of a representative group of common ethers. 3.Reactions of Ethers 1) Cleavage of Ethers by HBr and HI excess HX (X=Br or I) Protonation and cleavage of ether R O R' Br CH3CH2 O CH2CH3+ H diethyl ether Br R X + H H3C C X Br H H O CH2CH3 protonated ether Conversion of ethanol to ethyl bromide R' H3C C H +H H ethyl bromide O CH2CH3 ethanol Br H O + H CH2CH3 H Br O ethanol H2O + Br CH2CH3 CH2CH3 ethyl bromide H Overall reaction excess HBr/H2O 2 CH3CH2 Br CH2CH3 CH3CH2 O diethyl ether ethyl bromide We can rank the hydrohalic acids in order of their reactivity toward the cleavage of ethers: HI > HBr >> HCl Phenyl Ethers Phenyl ethers (one of the groups bonded oxygen is a benzene ring) react with HBr or HI to give alkyl halides and phenols. Phenols do not react further to give halides because the sp2 hybridized carbon atom of the phenol cannot undergo the SN2 (or SN1) reaction needed for conversion to the halide. O Br- CH2CH3 H CH2CH3 ethyl phenyl ether OH O Br H protonated ether + Br CH2CH3 phenol ethyl bromide (no further reaction) 2) Autoxidation of Ethers When ethers are stored in the presence of atmosperis oxygen, they slowly oxidize to produce hydroperoxides and dialkyl peroxides, both of which are explosive, Such a spontaneous oxidation by atmospheric oxygen called an autoxidation. OOH R H2 O C ether excess O2 (slow) R' R O CH R' hydroperoxide + H2 C dialkyl peroxide R O O R' Example H3C CH O excess O2 (weeks or months) CH H3C OOH H3C CH3 CH3 CH O C H3C diisopropyl ether hydroperoxide CH3 4. Synthesis of Ethers 1) Bimolecular Dehydration of Alcohols Bimolecular dehydration 2R OH Examples H+ R O R + H2O H3C CH3 + CH3 CH O O CH H3C CH3 diisopropyl peroxide 2CH3OH methyl alcohol H2SO4,140℃ H3C 2CH3CH2CH2OH H2SO4,140℃ n-propyl alcohol H C H3C O CH3 dimethyl ether (100%) CH3 H3CH2CH2C O n-propyl ether (75%) H2SO4,140℃ H C H2C + H2O CH2CH2CH3 + CH3 + H2O H2O OH isopropyl alcohol unimolar dehydration (no ether formed) 2) The Williamson Ether Synthesis R O R' X R O + R' X Examples OH OCH2CH3 (1).Na (2) CH3CH2-OTs cyclohexanol ethoxycyclohexane(92%) Synthesis of phenyl Ethers A phenol (aromatic alcohol) can be used as the alkoxide fragment (but not the halide fragment) for the Williamson ether synthesis. Phenols are more acidic than aliphatic alcohols (Section 10-6), and sodium hydroxide is sufficently basic to form the phenoxide ion. As with other alkoxides, the electrophile should have an unhindered primary alkyl group and a good leaving group. O OH CH2CH2CH2CH3 NO2 NO2 (1)NaOH (2)CH3CH2CH2CH2-I 2-nitrophenol 5. Some Important Ethers 2-butoxynitrobenzene(80%)