大学有机化学--醇醚

1、大学有机化学-醇醚HOCH3(1S,2S)-2-甲基环己醇甲基环己醇(1S,2S)-2-methylcyclohexanolOHHO(1R,4R)-2-环己烯环己烯-1,4-二醇二醇(1R,4R)-cyclohex-2-ene-1,4-diolCH2OH环戊基甲醇环戊基甲醇cyclopentylmethanolCH2OH苯甲醇苯甲醇 苄醇苄醇phenylmethanolCOHCH3CH32-苯基苯基-2-丙醇丙醇2-phenyl-2-propanolHOOHHO4-羟甲基羟甲基-1,8-辛二醇辛二醇4-hydroxymethyl-1,8-octanediolprimary alcohols (

2、伯醇伯醇, 1醇醇)secondary alcohols (仲醇仲醇, 2醇醇)tertiary alcohols (叔醇叔醇, 3醇醇) 10.1.2 ClassificationCOHROHHOHR+ H2OCOHROHRORR+ H2OCOHROHOHOOHR+ H2O10.1.3 StructureCH3OHCH3CH2OHHHHOHHH一元醇一元醇多元醇多元醇脂肪醇脂肪醇脂环醇脂环醇芳香醇芳香醇CH3CH2CH2OHCH3HHOHHHHOCH2CH2OHOHHHOHHHHOHOHHHHHOCH2CH2ClHClHOHHHHOCH2CH2OCH3HOHOHHCH3HOHOHHOOHOO

3、HHX10.2 Spectroscopy (光谱学光谱学)IR(红外红外)醇醇OH伸缩振动伸缩振动: 游离羟基游离羟基3650 3610(尖峰尖峰, 强度不定强度不定), 缔合羟基缔合羟基35003300 (宽峰宽峰) (形形成氢键后基团的伸缩频率都会下降，谱带变宽成氢键后基团的伸缩频率都会下降，谱带变宽)醇醇C-O伸缩振动伸缩振动126010001-己醇己醇CH3CH2CH2CH2CH2CH2OH顺顺-1,2-环戊二醇在低频区有红外吸收，既使稀释该吸收峰也不消失；反环戊二醇在低频区有红外吸收，既使稀释该吸收峰也不消失；反-1,2-环戊二醇无环戊二醇无此吸收，为什么？此吸收，为什么？NMR(核

4、磁共振氢谱核磁共振氢谱)HO-CH2-CH3羟基质子羟基质子 = 0.55.5 ppm氢键使羟基质子共振信号移向低场氢键使羟基质子共振信号移向低场, 常是一个较宽的单峰常是一个较宽的单峰分子内氢键分子内氢键, 其化学位移变化与溶液浓度无关其化学位移变化与溶液浓度无关加入几滴重水加入几滴重水(D2O), 再测定图谱，会使再测定图谱，会使羟基羟基质子信号消失质子信号消失MS(质谱质谱)醇的分子离子峰醇的分子离子峰M+经常较弱经常较弱, 甚至看不到甚至看不到, M-18或或M-15或或M-29峰丰度较高峰丰度较高CHCH2CH3OH+ H2O+ CH2CH3CHCH2CH3OHm/z = 136CH

5、=CHCH3m/z = 118CHOHm/z = 10710.3 ReactionsCOH + +Acidity and basic / nucleophilic -OH is a leaving group (very poor)SN2 or SN1E1 or E2Formation of esters(酯酯) and sulfonates(磺酸酯磺酸酯)Oxidation10.3.1 Acidity and Basic / Nucleophilic ROHAlkoxide ion(stablized by solution)O HH+ROO HH+H+-AcidityAcidity: 1

6、2 3 共轭碱的碱性？共轭碱的碱性？Acidity:RSO3H RCOOH ArOH H2O ROH RCCH H2 NH3 RHOHOHOHOHOHOHOHO2NO2NClClCH3OCH3ORONa + H2OROH + NaOHRONa + RCCHROH + RCCNaNH3 + RCCNaNaNH2 + RCCHROH + NaNH2RONa + NH3ROH + RMgXRH + MgX(OH)Reaction with active metals (与活泼金属反应与活泼金属反应)K Na Mg AlROH + NaRONa + H2ROH + NaHRONa + H2(CH3)2

7、CHOH + Al(CH3)2CHO3Al(CH3)3COH + K(CH3)3COK大体积强碱大体积强碱亲核性较弱亲核性较弱Basic / NucleophilicCO H + HACO HH+ A-+质子化醇质子化醇ROH + HIROH2 I-Good leaving group(CH3)3CBr + C2H5OH(CH3)3COC2H5 +72%CCH2H3CCH328%55叔卤代烷的溶剂解叔卤代烷的溶剂解(SN1), 醇的亲核性弱醇的亲核性弱盐10.3.2 Formation of esters and sulfonatesRCOOH, (RCO)2O or RCOClROHRCOO

8、R羧酸酯羧酸酯酰化反应酰化反应ROH + HONO2RONO2ROH + HONORONO硝酸酯硝酸酯亚硝酸酯亚硝酸酯RNO2硝基化合物硝基化合物 CH2ONO2CHONO2CH2ONO2The 1998 Nobel Prize in Medicine was awarded to the scientists (R. F. Furchgott, L. J. Ignarro, and F. Murad) who discovered that NO is an important signaling molecule (chemical messenger).ROHPOOHHOOH+POOHR

9、OOHPOOHROORROHPOORROORROH三硝酸甘油酯三硝酸甘油酯磷酸酯磷酸酯ROSOHOOROH + HOSOHOOROHROSOROOSulfates(硫酸酯硫酸酯)Me2SO4硫酸二甲酯是个很好的甲基化试剂硫酸二甲酯是个很好的甲基化试剂CH3OSOCH3OOCH3CH2OH +baseCH3CH2OCH3SN2Sulfonates(磺酸酯磺酸酯)ROHRSO2ClRSO2ORbase+OCH2CH3HbaseSOCH3ClOSOCH3OCH2CH3OMsCl+OCH2CH3HbaseSOOCH2CH3OCH3SOClOCH3TsCl磺酸酯是个很好的烷基化试剂磺酸酯是个很好的烷基化

10、试剂SOOORCH2R- Nu+SOO-ORRCH2Nu +SN2常用亲核试剂常用亲核试剂: 烷氧基负离子烷氧基负离子, 卤素负离子等卤素负离子等CH3OSO2C2H5ONaC2H5OCH3CRRHOH + ClTsretention-HClCRRHOTsROSOROOROHROHbaseRORSulfates (硫酸酯硫酸酯)Sulfonates (磺酸酯磺酸酯)baseROHRSO2ClRSO2ORbaseNu-RNuO O H HT Ts sC Cl lO O T Ts sH HC Cl l( (S S) )- -2 2- -O O c ct ta an no ol l( (S S) )

11、- -2 2- -O O c ct ty yl l t to os sy yl la at te e+ +p py yr ri id di in ne e+ +T To os sy yl lc ch hl lo or ri id de eO O- -N N a a+ +O OO O T Ts sO OO ON N a a+ +O O T Ts s- -( (S S) )- -2 2- -O O c ct ty yl l t to os sy yl la at te e+ +S So od di iu um ma ac ce et ta at te ee et th ha an no ol lS

12、 SN N2 2+ +( (R R) )- -2 2- -O O c ct ty yl l a ac ce et ta at te eOOOODue to its suitable properties and the low cost, DEHP (邻苯二甲酸二邻苯二甲酸二(2-乙基乙基)己酯己酯) is widely used as a plasticizer in manufacturing of articles made of PVC. Plastics may contain 1% to 40% of DEHP. 10.3.3 Nucleophilic Substitution(亲

13、核取代亲核取代)ROHRNuNu-OH is a leaving group (very poor)10.3.3.1 Reaction with HXROHHXRXReactivity of HX HI HBr HClReactivity of ROHBenzyl, allyl, 3 2 1CCH3OHCH3H3C+ HCl (concd)25 oC+ H2O94%CCH3ClCH3H3CCH3CH2CH2CH2OH+refluxCH3CH2CH2CH2BrHBr (concd)(95%)用用Lucas试剂（盐酸试剂（盐酸+氯化锌）鉴别各类醇氯化锌）鉴别各类醇CHHROHH+RCH2OHH+M

14、echanism1alcohols and methanolSN2X+CHHRCHHROHH+X -OHH+ORHORHZnCl2-+ZnCl2ORHZnCl2-+Cl -ClR+Zn(OH)Cl2-2, 3, allylic, and benzylic alcoholsSN1+ HfastCCH3CH3H3COHHCCH3OCH3H3CH+slowCCH3CH3H3COHHOHH+H3CCCH3CH3+fastCCH3CH3H3CClCl -H3CCCH3CH3+外消旋化、重排外消旋化、重排与与HBr反应速度反应速度CH3OCH=CHCH2OH CH3CH=CHCH2OH ClCH=CHCH

15、2OH NCCH=CHCH2OHOHHBrBrBr+64%36%HOHBrBrBr+Neighboring-group Participation(邻基参与邻基参与)CH3BrHCH3HOHHBrCH3BrHCH3HBrCH3HBrCH3BrH+苏式苏式苏式外消旋体苏式外消旋体BrOHH3CCH3HHH+BrOH2H3CCH3HHBrH3CCH3HHBr-BrBrH3CCH3HHBrBrCH3H3CHH+CH3HBrCH3HOHHBrCH3HBrCH3HBr赤式赤式赤式内消旋体赤式内消旋体10.3.3.2 Reaction with Other ReagentsPX3或或PX5+ PBr3+C

16、2H5OHRBrH3PO3C2H5OH + PCl5RCl+ HClPOCl3C2H5OHPI2RI1and 2alcohols seldom rearrange (SN2)RCH2OHBrPBrBr+BrRCH2OPBr2H+-RCH2BrA good leaving groupBr -RCH2OPBr2H+ HOPBr2+PBr3-10 to 0 oC4 h(55-60%)(CH3)2CHCH2OH(CH3)2CHCH2BrSOCl2 (亚硫酰氯亚硫酰氯 氯化亚砜氯化亚砜)reflux+ SOCl2+ROHRClHCl + SO2紧密离子对紧密离子对SNiretention of conf

17、igurationA 3amine is added to promote the reaction inversion of configuration (SN2) + SOCl2pyridine(91%)CH2OHH3COCH2ClH3COMechanismheat+CCH2OCCHOHHAR OSOOCH3Nu-RNuROHTsCl10.3.3.3 Reactions via Sulfonates or Sulfates (通过磺酸酯或硫酸酯反应通过磺酸酯或硫酸酯反应)CN-I- / 丙酮丙酮RO-构型保持构型保持 构型翻转构型翻转10.3.4 EliminationIntermolec

18、ular Dehydration of Alcohols (消除反应消除反应醇的分醇的分子内脱水子内脱水) E1OHH+t-BuOKHOTsClTsORCH2OHRCOHRCOOHOO10.3.5 Oxidation(氧化氧化)RCHOHRCORRO10.3.5.1 KMnO4 and MnO2RCH2OHH3O+RCO2HOH +KMnO4RCO2 K+H2Oheat MnO2OHKMnO4COOH74%伯醇分子中如有烯键，亦可被氧化伯醇分子中如有烯键，亦可被氧化仲醇叔醇用酸性高锰酸钾氧化易使碳链断裂仲醇叔醇用酸性高锰酸钾氧化易使碳链断裂新制新制MnO2KMnO4 + MnSO4 + NaO

19、HMnO2 + K2SO4 + Na2SO4 + H2OC COHC CCH OHMnO2MnO2C CC HOC CCO其他羟基以及烯键不受影响其他羟基以及烯键不受影响MnO2HOHOOHOHOOH10.3.5.2 Chromic acid (铬酸铬酸) Na2Cr2O7/H2SO4, CrO3/HOAc, CrO3.Py.HCl/CH2Cl2, CrO3 / H2SO4acetone (Jones试剂试剂) pyridinium chlorochromate(氯铬酸吡啶嗡盐氯铬酸吡啶嗡盐) PCC (Sarrett试剂试剂)如果醛的沸点低，可蒸出避免进一步氧化如果醛的沸点低，可蒸出避免进一

20、步氧化Na2Cr2O7/H2SO4RCH2OHRCO2HRCHONa2Cr2O7/H2SO4Na2Cr2O7/H2SO4CH3CH2CH2OHNa2Cr2O7/H2SO4CH3CH2CHO50%Na2Cr2O7/H2SO4OHO85%OHH2CrO4AcetoneO35oCPCC +NCrO3Cl-CrO3+ HClNH+(C2H5)2C CH2OHCH3PCC(C2H5)2CCHCH3O25oC+CH2Cl294%80%OHPCCCH2Cl2O84%PCCCH2Cl2OHHO10.3.5.3 Nitric acid(硝酸硝酸) 10.3.5.4 Oppenauer OxidationCH O

21、H +CH3CCH3O(i-PrO)3AlC OCH3CHCH3OH+可逆反应可逆反应+CH3CCH3O(i-PrO)3AlCH3CHCH3OH+OHO+CH3CCH3O(t-BuO)3AlCH3CHCH3OH+CH2OHCHO10.3.5.5 Pfizner-Moffatt OxidationCH3SCH3ODCCN C NN,N-dicyclohexylcarbodiimide (N,N-二环己基碳二亚胺二环己基碳二亚胺)脱水剂脱水剂CH3SCH3ODCCO2NCH2OHO2NCHO10.4 Reactions of Glycols (邻二醇的反应邻二醇的反应)10.4.1 Oxidati

22、ve Cleavage(氧化断裂氧化断裂)Periodic acid (高碘酸高碘酸)OHOHH5IO6OHCCHO高碘酸或醋酸铅高碘酸或醋酸铅C OHC OHIOHHOHOOHOO+IOHOOOHOOCCMechanism邻二醇邻二醇( -二醇二醇), -羟基醛羟基醛/酮酮/酸酸, -氨基醛氨基醛/酮酮/酸酸, 1,2-二酮二酮(-二酮二酮), 1-氨基氨基-2-羟基化合物羟基化合物均可被高碘酸分解均可被高碘酸分解OHOHt-BuOHOH很慢很慢Bu-tOHOHLead acetate (醋酸铅醋酸铅)：Pb(OAc)410.4.2 Pinacol Rearrangement (频哪醇重排频

23、哪醇重排)CH3CCH3OHCH3CCH3OHH+CH3COCH3CCH3CH3CH3CCH3OHCH3CCH3OHH+CH3CCH3OHCH3CCH3OH2CH3CCH3OHCH3CCH3-H2OCH3COHCH3CCH3CH3HCPhOHCPhCH3OHH+1) 形成最稳定的碳正离子形成最稳定的碳正离子HCPhOHCPhCH3Mechanism2) 提供电子的基团发生迁移提供电子的基团发生迁移HCPhOHCPhCH3HCOCPhPhCH33) 迁移基团与离去基团应处于反位迁移基团与离去基团应处于反位H3COH2CH3HOOH3CCH3H3COHOHH3C10.5 Preparation o

24、f AlcoholsAlkenesAlkyl HalidesCarbonyl CompoundsAlcoholsGrignard SynthesisCH3OHCH3HOCH3OH2CH3HOH+- H2OHO10.5.1 Via Hydrolysis of Alkyl Halides(通过卤代烃的水解通过卤代烃的水解)It is rarely used for the synthesis of alcohols, since alkyl halides are normally prepared from alcohols.很少用卤代烃的水解来制备醇，因为多数情况下卤代烃比醇贵重，常用醇来制备

25、卤很少用卤代烃的水解来制备醇，因为多数情况下卤代烃比醇贵重，常用醇来制备卤代烃。代烃。CH3Br + HO- CH3OH + Br- (CH3)3CBr + H2O (CH3)3COH + HBr H3CCH3CH3CH2ClH2O, Ca(OH)2H3CCH3CH3CH2OH(78%)RX + HO- ROH + X-10.5.2 Via Reactiontion of Alkenes (通过烯烃反应通过烯烃反应)H2SO4H+H2OH C C OSO3HH2OH C C OH1) BH32) H2O2/OH-H C C OHH C C OHCCCCOOsOOOH2OCCOH OH+OsOO

26、OOH2O, H+ or OH-HOOHRCO3HNa2CO3OCXCOHX2 / OH-Oxymercuration-demercuration of alkenes(烯烃的羟汞化烯烃的羟汞化-去汞化去汞化)CHgOAcCOHH2OHg(OAc)2NaBH4CHCOHThe reactions take place very rapidly at room temperature;The overall reaction gives alcohols in very high yields, usually greater than 90%; Rearrangements of the ca

27、rbon skeleton seldom occur.* Mercury compounds are extremely hazardous!Markovnikov additionanti addition(反式加成反式加成)Mechanism(机理机理)H2OHg(OAc)2NaBH4OHCH=CH2CCH3H3CH2OHg(OAc)2NaBH4CH3CHCCH3H3CCH3CH3OHCH3(CH2)2CHCH2Hg(OAc)2CH3(CH2)2CHCH2HgOAcNaBH4OH(93%)THF-H2OOH-(1 h)CH3(CH2)2CHCH2HOH(15s)10.5.3 Via Red

28、uction of Carbonyl Compounds or Derivatives of Carboxylic Compounds (通过羰基化合物或羧酸衍生物还原通过羰基化合物或羧酸衍生物还原) H RCHORCH2OH H RCRORCHROH H RCOHORCH2OH+ H RCORORCH2OHROHHydrogenation (H2 with Raney nickel): Also reduces any C=C bondsSodium in alcohol Lithium aluminum hydride (LiAlH4): reduces acids, esters, al

29、dehydes, and ketonesSodium borohydride (NaBH4): reduces only aldehydes and ketones10.5.4 Grignard Synthesis(格氏试剂合成法格氏试剂合成法)RMgX+CO1. ether2. H3O+X -CROH+MgX21) Grignard Reagents React with Formaldehyde to Give a 1 Alcohol.2) Grignard Reagents React with All Other Aldehydes to Give 2 Alcohols.3) Grig

30、nard Reagents React with Ketones to Give 3 Alcohols.+H3O+ RMgXHCHOOCHHROHCHHRMgX+H3O+ RMgXRCHOOCRHROHCRHRMgX+H3O+ RMgXRCROOCRRROHCRRRMgX+H3O+C6H5MgBrHCHOOMgBrC6H5CH2Et2OC6H5CH2OH90%+H3O+CH3CH2MgBrH3CCHOEt2OCH3CH2CHOHOMgXCH3CH2CCH3HCH380%+NH4ClCH3CH2CH2CH2MgBrH3CCH3COEt2OOMgXCH3CH2CH2CH2CCH3CH3OHCH3C

31、H2CH2CH2CCH3CH3H2O92%+H3O+RMgXRCROOOCRORMgXOHCRRRRInitial product (unstable)-ROMgXspontaneouslyRCRORMgXOMgXCRRR4) Esters React with Two Molar Equivalents of a Grignard Reagent to Form 3 Alcohols+H3CCC2H5OOOMgBrCCH3OCH2CH3CH3CH2OHCH3CH2CCH3CH2CH3H3CCCH3CH2OCH3CH2MgBrOMgXCH3CH2CCH3CH2CH3CH3CH2MgBr-C2H

32、5OMgBrNH4ClH2O67%如用甲酸酯，则得仲醇如用甲酸酯，则得仲醇+CH3CH2CH2CH2MgBr85%HCOOC2H5(CH3CH2CH2CH2)2CHOH也可使用碳酸酯也可使用碳酸酯+CH3CH2MgBr85%COOCH3CH3OCCH2CH3HOCH2CH3CH2CH3CH2H2CO+H+ RMgXRCH2CH2O -Mg2+X-RCH2CH2OHSN2CH2H2CO+H+C6H5MgBrC6H5CH2CH2OMgBrEt2OC6H5CH2CH2OH5) Reactions of Grignard Reagents with EpoxidesCHH2CO+C6H5MgBrCH3

33、H+C6H5CH2CHOMgBrEt2OC6H5CH2CHOHCH3CH3+H3O+ + RLiCOOCROHCRLi6) 其他类似试剂其他类似试剂+H2C CHLiC6H5CHOCH2=CHCHC6H5OH NaCH3 CCH3 O+H3CCCH3CCCCCH3CH3ONa H3O+H3CCCCCH3CH3OH炔醇炔醇CMgBrC2H5CHOCCHC2H5OH+C6H5CC6H5CC6H5MgBrCH2CH3COCH3CH2+1. Et2O2. NH4ClCH2CH3CC6H5OHCH3CH2H2OCH3CH2MgBr+C6H5CCH3CH2O1. Et2O2. NH4ClH2OCH2CH3

34、CC6H5OHCH3CH21. Et2O2. NH4ClH2OCH2CH3CC6H5OHCH3CH2+CH3CH2MgBr2C6H5OCH3CORetrosynthetic Analysis (逆合成分析逆合成分析)CH2CH3CC6H5OHCH3CH2Ethers (醚醚)C2H5OC2H5 diethyl ether (乙醚乙醚) First general anestheticCauses nausea and vomiting, and is highly flammableCH3OC(CH3)3 Methyl tert-butyl ether (MTBE 甲基叔丁基醚甲基叔丁基醚)

35、Additive to improve gasoline performance as an antiknock agent and to reduce emission of CO in automotive exhaust gas Sulfide(硫醚硫醚) RSRROR10.6 Structure, Classification and Nomenclature10.6.1 StructureC CH H3 3- -O O - -C CH H3 3C CH H3 3C CH H2 2- -O O - -C CH H2 2C CH H3 3D D i im m e et th hy yl

36、l e et th he er rD D i ie et th hy yl l e et th he er rsp310.6.2 ClassificationR-O-R simple ether(单醚单醚), symmetrical ether(对称醚对称醚)R-O-R complex ether(混醚混醚), unsymmetrical ether(不对称醚不对称醚)aliphatic ether(脂肪醚脂肪醚)aromatic ether(芳香醚芳香醚)OCH3OOsp2p- 共轭共轭Ocyclic ether(环醚环醚)OOOOOEpoxide, oxirane(环氧化合物环氧化合物,

37、环氧乙烷环氧乙烷)Crown ether(冠醚冠醚)OOOOOOOOOOOO10.6.3 NomenclatureCommon NamesCH3-O-CH3甲醚甲醚dimethyl ethermethyl etherO二乙烯基醚二乙烯基醚C6H5OC6H5二苯基醚二苯基醚CH3-O-CH2CH3甲乙醚甲乙醚CH3CH2-O-CH2Cl乙基氯甲基醚乙基氯甲基醚O甲基叔丁基醚甲基叔丁基醚O异丁基仲丁基醚异丁基仲丁基醚OO烯丙基乙炔基醚烯丙基乙炔基醚甲基环己基醚甲基环己基醚O苯乙醚苯乙醚IUPAC NamesROalkoxy groupO2-甲基甲基-2-甲氧基丙烷甲氧基丙烷2-methoxy-2-

38、methylpropaneCH3-O-CH2CH2CH31-甲氧基丙烷甲氧基丙烷O2-异丁氧基丁烷异丁氧基丁烷 2-(2-甲基丙氧基甲基丙氧基)丁烷丁烷2-isobutoxybutaneEpoxide, oxirane (环氧化合物环氧化合物, 环氧乙烷环氧乙烷)O环氧乙烷环氧乙烷氧化乙烯氧化乙烯123O2,2-二甲基环氧乙烷二甲基环氧乙烷氧化异丁烯氧化异丁烯O(S)-2,2-二甲基二甲基-3-异丙基环氧乙烷异丙基环氧乙烷O甲基环氧乙烷甲基环氧乙烷1,2-环氧丙烷环氧丙烷O1,3-环氧丙烷环氧丙烷O2-甲基甲基-1,2-环氧丙烷环氧丙烷O2,4-二甲基二甲基-2,3-环氧戊烷环氧戊烷O2,3,

39、4-三甲基三甲基-3,4-环氧环氧-1-戊烯戊烯O1,2-环氧环己烷环氧环己烷氧化环己烯氧化环己烯OOOOOOOOOOOO18-冠冠-610.7 SpectroscopyIR醚醚COC伸缩振动伸缩振动12751020cm-1(强吸收强吸收)NMR1H-C-O = 3.54 ppmCH3CH2CH2OCH2CH2CH3MS醚的分子离子峰醚的分子离子峰M+常较弱常较弱CH3CH2CH2CH2OCH2CH2CH2CH3M=130m/z=57m/z=87 分子离子失去分子离子失去C3H7.分子离子失去分子离子失去C4H9O.10.8 Reactions10.8.1 Autoxidation(自动氧化自

40、动氧化) BasidityROR+H+RORHROR+BF3RORBF3-形成钅羊盐和络合物的能力形成钅羊盐和络合物的能力: ROR ROAr ArOArThe 1987 Nobel Prize in Chemistry was awarded to Charles J. Pedersen, Donald J. Cram, and Jean-Marie Lehn for their work on crown ethers and related compounds (host-guest chemisty). CH3OCH3HBrCH3OCH3H_Br_+10.8.4 Acid-Cataly

41、ed CleavageReactivity: HI HBr HClRORHXRX + ROHHXRXEthers with 1 alkyl groups react by an SN2Br_+CH3OCH3HBr CH3+HOCH3RCH2OCH3HI+CH3IRCH2OHHIRCH2ICH2CH3OCH3CHOCH3CHHICH3CH2CH3HI,H2OCH3+SN2OHIOHI+OHI+OCH2CH3HBr, H2ORefluxOHCH3CH2Br+Phenol cannot react further to become halideAllylic, benzylic, and 3o e

42、thers cleave via E1/SN1CH3CH3CH3CCH2CH2CH3OCH3CH3CH3CBrHOCH2CH2CH3HBr+OHBrOH- Br-CH3OHCH3H3CCH3+混醚混醚C-O断裂次序断裂次序:Allyl, benzyl, 3烷基烷基2烷基烷基, 1烷基烷基, CH3芳基芳基ArOAr在在HI作用下醚键不断裂作用下醚键不断裂C CH2C6H5H3COH3O+C6H5COCH3CH3OH10.8.5 Hydrogenolysis of Benzyl Ethers (苄基醚的氢解苄基醚的氢解)CH2O RH2 / Pd-CCH3ROH+This Reaction is

43、 useful for protection of -OHOHOHOHOCH3OCH3OOHPhCH2Clpyridine1) BH3 / THF2) H2O2 / OH-OOHOCH3OCH3OCH3OH2, Pd/COHOHBrBrOHHBrBrBr10.8.6 Ring Opening of Epoxide (环氧乙烷的开环环氧乙烷的开环)ORNu- anionic nucleophileUnder conditions of acid catalysisRing Opening in BaseORNaOHRONaNH3NaCNNaN3C6H5LiRC CNaRMgXLiAlH4RHOOHRHOORRHOCNRHON3RHOC6H5RHOC CRRHORRHOHRHONH2OC2H5ONa / C2H5OHOC2H5OH() OCH3H3CHC6H5