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1 hapter 10 Alcohols and Ethers Alcohols (醇) (E)-6,7-二甲基-6-壬烯-1-醇 (E)-6,7-dimethyl-6-nonen-1-ol 1-甲基环戊醇 1-methylcyclopentanol 10.1 Nomenclature, lassification and Structure Nomenclature 2 (2,5S)-7-甲基-2,5-辛二醇 (2,5S)-7-methyl-2,5-octanediol lassification primary alcohols(伯醇, 1º醇) secondary alcohols(仲醇, 2º醇) tertiary alcohols(叔醇, º醇) ' Structure sp 22 2 ' 2 22l l 2-苯基-2-丙醇 2-phenyl-2-propanol 苯甲醇苄醇 phenylmethanol 22 4-羟甲基-1,8-辛二醇 4-hydroxymethyl-1,8-octanediol 2 环戊基甲醇 cyclopentylmethanol (1,4)--2-环己烯-1,4-二醇 (1,4)-cyclohex-2-ene-1,4-diol (1S,2S)-2-甲基环己醇 (1S,2S)-2-methylcyclohexanol 5,6,6-三甲基-5-乙基-2-庚醇 5-ethyl-5,6,6-trimethyl-2-heptanol Ph overtone 10.2 Spectroscopy(光谱学) sp I(红外) sp2 醇伸缩振动: 游离羟基 (尖峰, 强度不定), 缔合羟基500~00 (宽峰) (形成氢键后基团的伸缩频率都会下降谱带变宽) 醇-伸缩振动1260~ ring - Mono Subst. Ph 75 & 697 cm 己醇 1

ydrogen-bonded - (very dilute solution) MS(质谱) 10.

2 NM(核磁共振氢谱) 羟基质子δ=0.5~5.5ppm 氢键使羟基质子共振信号移向低场, 常是一个较宽的单峰分子内氢键, 其化学位移变化与溶液浓度无关加入几滴重水(D2), 再测定图谱会使羟基质子信号消失 -2- (a) ydrogen-bonded - only (neat liquid) (b) Free and ydrogen-bonded - (dilute solution) (c) Free and ydrogen-bonded - (very dilute solution) MS(质谱) 10. eactions 醇的分子离子峰M经常较弱, 甚至看不到, M-18或M-15或M-29峰丰度较高 Acidity and basic / nucleophilic δ SN2 or SN1 - is a leaving group (very poor) δ 2 δ E1 or E2 Formation of esters(酯) and sulfonates(磺酸酯) xidation Acidity and Basic / Nucleophilic Acidity 2 = 2 - Alkoxide ion (stablized by solution) m/z = 118 m/z = 16 Acidity: 1º >2º >º 2 m/z = 107 Acidity: S > > Ar > 2 > > > 2 > N > eaction with active metals(与活泼金属反应) K Na Mg Al Na 2 Na 亲核试剂强碱 Na 2 Na 2N > > 2N > l l > > > ()2 Al [()2]Al () K ()K 大体积强碱亲核性较弱 Good leaving group Basic / Nucleophilic Na 2 Na N Na Na Na NaN2 NaN2 Na N 'MgX ' MgX() A A质子化醇盐 I 2 I- BF BF- 55 ()25 2 叔卤代烷的溶剂解(SN1), 醇的亲核性弱 72% 28% () 25 2

3 10..2 Formation of esters and sulfonates ', (') 2 or 'l ' 羧酸酯酰基化反应 N 2 N 2 N 2 N 2 N 2 2 N 2 三硝酸甘油酯 P P Pl () P N 硝酸酯亚硝酸酯 P P N 2 硝基化合物磷酸酯 Sulfates( 硫酸酯 ) S S S () 2 S 2 2 S 4 Me 2 S 4 硫酸二甲酯是个很好的甲基化试剂 S base 2 S 2 S N 2 Sulfonates( 磺酸酯 ) 'S 2l base S 'S 2 l 2 Msl S Pl 5 S l Pl l S l 2 Tsl base base S 2 MsEt S 2 TsEt ' l Ts retention -l 'S 2 磺酸酯是个很好的烷基化试剂 ' S ' S 2 - N 2 Nu 2 Nu ' S 常用亲核试剂 : 烷氧基负离子, 卤素负离子等 S Na 2 5 Ts Nucleophilic Substitution( 亲核取代 ) Nu - Nu - is a leaving group (very poor) eaction with X X X eactivity of X I > > l Na 2 S 4 KI P 4 eactivity of Benzyl, allyl, º > 2º > 1º 用 Lucas 试剂鉴别各类醇叔醇易消除, 故低温 Nu - ' Ts inversion S N 2 Nu ' - Ts l (concd) 25 o 94% (concd) reflux l (95%) Mechanism 1 alcohols and methanol S N 2 2 X - X Znl 2 - Znl 2 - l - Znl 2 l [Zn()l 2 ] - 2,, allylic, and benzylic alcohols S N 1 slow l - fast fast l 外消旋化 E1 重排

4 Neighboring-group Participation( 邻基参与 ) eaction with ther eagents 苏式苏式外消旋体 PX 或 PX 5 P 2 5 P 2 5 Pl 5 l l Pl 2 5 P I 2 I 2-1 and 2 alcohols seldom rearrangement(s N 2) - 2 P 2 P 2-2 P 2 2 P 2 A good leaving group ( ) 2 2 P -10 to 0 o 4 h ( ) 2 2 (55-60%) Sl 2 ( 亚硫酰氯氯化亚砜 ) reflux Sl 2 l l S 2 1 and 2 alcohols seldom rearrangement 2 l S l l 2 S - l S N i retention of configuration -l 2 pyridine Sl 2 l 2 S 2 l l - -S 2 S 2 2 l 紧密离子对 A amine is added to promote the reaction inversion of configuration (S N 2) eactions via Sulfonates or Sulfates( 通过磺酸酯或硫酸酯反应 ) Nu Tsl - N - S Nu I - / 丙酮 - 构型保持构型翻转 S 碱 Elimination Intermolecular Dehydration of Alcohols ( 消除反应醇的分子内脱水 ) E1 A heat 2 (91%) Tsl Ts xidation( 氧化 ) 2 [] ' [] t-buk [] ' KMn 4 and Mn 2 2 KMn K heat 2 KMn 4 74% 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 Mn 2 新制 Mn 2 KMn 4 MnS 4 Na Mn 2 K 2 S 4 Na 2 S 4 2 Mn 2 Mn 2 其他羟基以及烯键不受影响 4

5 hromic acid( 铬酸 ) 烯键不受影响 Na 2 r 2 7 / 2 S 4, r /Ac, r. 2Py/ 2 2 l (Sarrett 试剂 ), r. Py. l/ 2 l 2, r / 2 S 4 acetone (Jones 试剂 ) pyridinium chlorochromate P 铬酸氧化的机理 Na 2 r 2 7 / 2 S 4 Na 2 2 r 2 7 / 2 S 4 Na 2 r 2 7 / 2 S 4 2 如果醛的沸点低, 可蒸出避免进一步氧化 2 2 Na 2r 2 7 / 2 S % Nitric acid( 硝酸 ) ppenauer xidation 2 不影响双键对酸不稳定的基团不受影响 (i-pr) Al 可逆反应 (i-pr) Al (t-bu) Al Pfizner-Moffatt xidation S D N N N,N'-dicyclohexylcarbodiimide N,N - 二环己基碳二亚胺脱水剂, 尤用于肽的合成 S S 2 N 2 2 N D N N 10.4 eactions of Glycols( 邻二醇的反应 ) Vicinal Diols xidative leavage( 氧化断裂 ) 高碘酸或醋酸铅 Periodic acid( 高碘酸 ) Lead acetate ( 醋酸铅 ):Pb(Ac) Pinacol earrangement Mechanism Mechanism I I 2 邻二醇 ( α- 二醇 ), α- 羟基醛 / 酮 / 酸, α- 氨基醛 / 酮 / 酸, 1,2- 二酮 (α- 二酮 ), 1- 氨基 -2- 羟基化合物 5

6 Ph Ph Ph 1) 形成最稳定的碳正离子 Ph 2) 提供电子的基团发生迁移 Ph Ph Ph Ph 10.5 Preparation of Alcohols Alkenes Alkyl alides Alcohols arbonyl ompounds ) 迁移基团与离去基团应处于反位 2 Grignard Synthesis Via ydrolysis of Alkyl alides( 通过卤代烃的水解 ) X - X - It is rarely used for the synthesis of alcohols, since alkyl halides are normally prepared from alcohols. s s Na 2 2 2, or Via eactiontion of Alkenes( 通过烯烃反应 ) 2 S 4 2 S 1) B 2) 2 2 / - Mn Mn 2 not very effective 2 several steps Mn 2 X 2 / - X xymercuration-demercuration of alkenes( 烯烃的羟汞化 - 去汞化 ) gac 2 NaB 4 g(ac) 2 还原 The reactions take place very rapidly at room temperature. The overall reaction gives alcohols in very high yields, usually greater than 90% earrangements of the carbon skeleton seldom occur. Mercury compounds are extremely hazardous. Mechanism( 机理 ) Acg g( ) 2 g 2 NaB Markovnikov addition anti addition ( 反式加成 ) Via eduction of arbonyl ompounds or Derivatives of arboxylic ompounds ( 通过羰基化合物或羧酸衍生物还原 ) ' ' [ ] [ ] [ ] [ ] 2 ' 2 2 ' ydrogenation ( 2 with aney nickel): Also reduces any = bonds Sodium in alcohol Lithium aluminum hydride (LiAl 4 ): reduces acids, esters, aldehydes, and ketones Sodium borohydride (NaB 4 ): reduces only aldehydes and ketones 6

7 Grignard Synthesis( 格氏试剂合成法 ) MgX Mechanism 1. ether MgX 2 2. X - MgX Mg 2 X - - Mg 2 X - X - 1) Grignard eagents eact with Formaldehyde to Give a 1º Alcohol. 2) Grignard eagents eact with All ther Aldehydes to Give 2º Alcohols. ) Grignard eagents eact with Ketones to Give º Alcohols. 4) Esters eact with Two Molar Equivalents of a Grignard eagent to Form º Alcohols. 5) eactions of Grignard eagents with Epoxides 2 etrosynthetic Analysis ( 逆合成分析 ) Mg Et 2 2. N 4 l Mg 2 2 Mg Et 2 2. N 4 l 2 1. Et 2 2. N 4 l 2 -Phenyl--pentanol Ethers ( 醚 ) 10.6 Structure, lassification and Nomenclature Structure 111.7º sp lassification -- simple ether( 单醚 ), symmetrical ether( 对称醚 ) -- complex ether( 混醚 ), unsymmetrical ether( 不对称醚 ) aliphatic ether( 脂肪醚 ) aromatic ether( 芳香醚 ) cyclic ether( 环醚 ) Epoxide, oxirane( 环氧化合物, 环氧乙烷 ) rown ether( 冠醚 ) Dimethyl ether Diethyl ether p-π 共轭 121º sp Nomenclature ommon Names -- 甲醚 dimethyl ether methyl ether -- 2 甲乙醚二乙烯基醚 l 乙基氯甲基醚二苯基醚甲基叔丁基醚 IUPA Names 2- 甲基 -2- 甲氧基丙烷 2-methoxy-2-methylpropane alkoxy group Epoxide, oxirane( 环氧化合物, 环氧乙烷 ) 1 2 环氧乙烷氧化乙烯 2,2- 二甲基环氧乙烷氧化异丁烯 1- 甲氧基丙烷 2- 异丁氧基丁烷 2-(2- 甲基丙氧基 ) 丁烷 2-isobutoxybutane (S)-2,2- 二甲基 -- 异丙基环氧乙烷异丁基仲丁基醚烯丙基乙炔基醚甲基环己基醚苯乙醚 7

2 1 1,2- 环氧丙烷 1 2 4 5 2,4- 二甲基 -2,- 环氧戊烷 2 1 1,- 环氧丙烷 2 1 2- 甲基 -1,2- 环氧丙烷 2,,4- 三甲基 -,4- 环氧 -1- 戊烯

5~4ppm 2 2 2 2 MS 醚的分子离子峰 M 常较弱, β- 裂解产生丰度较高的碎片离子峰, 亦有 α - 裂解 m/z=57 分子离子失去 4 9.

8 2 1 1,2- 环氧丙烷 ,4- 二甲基 -2,- 环氧戊烷 2 1 1,- 环氧丙烷甲基 -1,2- 环氧丙烷 2,,4- 三甲基 -,4- 环氧 -1- 戊烯 1,2- 环氧环己烷 10.7 Spectroscopy I 醚伸缩振动 1275~1020cm -1 ( 强吸收 ) 18- 冠 -6 NM 1 -- δ=.5~4ppm MS 醚的分子离子峰 M 常较弱, β- 裂解产生丰度较高的碎片离子峰, 亦有 α - 裂解 m/z=57 分子离子失去 M= eactions Autoxidation( 自动氧化 ) Basidity 形成钅羊盐和络合物的能力 : > Ar > ArAr ' ' - BF BF ' ' m/z=87 分子离子失去 7. 8

9 _ Acid-atalyed leavage ' X X ' X 'X eactivity: I > >> l Ethers with 1º alkyl groups react by an S N 2 Alcohol is protonated, halide attacks, and another molecule of alkyl bromide is formed Allylic, benzylic, and o ethers cleave via E1/S N 混醚 - 断裂次序 : Allyl, benzyl, 烷基 >2 烷基,1 烷基, > 芳基 ArAr 在 I 作用下醚键不断裂 ydrogenolysis of Benzyl Ethers( 苄基醚的氢解 ) 2 2 / Pd- This eaction is useful for synthesis Protection of ing pening of Epoxide ( 环氧乙烷的开环 ) Under conditions of acid catalysis Nu - anionic nucleophile ing pening in Base Na S N 'Na ' NaN N NaN N Li 6 5 ' Na ' 'MgX ' LiAl 4 N N 2 ing pening in Acid / 2 / ' N X ' N X / B B o carbocation δ 2 δ The reaction is S N 1 like 10.9 Preparation Acid-atalyzed Intermolecular Dehydration of Alcohols If temperature is too high, alkene forms S o º alcohols S N 2 2 S o and o alcohols E1 140 o S

10 The Williamson Synthesis of Ethers Preparation of Epoxides( 环氧化合物的制备 ) - Na ' L ' S N 2, primary or secondary alkyi L=, I, S 2, S 2 Epoxidation of alkenes Acid-catalyzed Addition of Alcohols to Alkenes 2 S protecting group Alkoxymercuration of Alkenes( 烯的烷氧汞化 ) g( NaB 4, - 2 F ) 2 /TF- g 2 F Base-promoted ring closure of vicinal halohydrins( 碱促进下 β - 卤代醇的环合 ) / 2 Na Na 2 mesomer 分子内 S N 2 racemate racemate SUMMAY Alcols Nomenclature eactions Preparation Ethers Nomenclature eactions Preparation 10

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<4D6963726F736F667420576F7264202D20B5DA39D5C220B4BCA1A2B7D3BACDC3D12E646F63> 第 9 章醇酚醚及消除反应醇酚和醚都是烃的含氧衍生物它们可以看作是水分子中的氢原子被烃基取代得到的化合物 R Ar R R 水醇酚醚醇和酚分子中都含有羟基 (-), 酚是羟基直接与苯环相连 ; 醇是羟基与脂肪族碳相连 9.1 醇 9.1.1