文本有機(jī)化學(xué)2醚

1、Ether第十一章醚a(bǔ)nic Chemistry A (1) By Prof. Li Yan-MeiTsinghua UniversityContent11.111.211.311.411.511.6Structure and nomenclature Physical and Spectral properties Chemical reactionsPreparation EpoxidesSource and usages11.1Structure and nomenclature11.1.111.1.211.1.3Structure ClassificationNomenclature1

2、1.1.1Structure結(jié)構(gòu)O atomOsp3 hybridizationtwo unshared pairRROOOHHHCH3H3CCH3Bond angle105o108.9o111.7o11.1.2Classification分類R = RSymmetric ether/ Simple ether簡(jiǎn)單醚ORRR RAsymmetric ether混合醚OR connected with REpoxide環(huán)醚（環(huán)氧化物）11.1.3Nomenclature命名(A) 無環(huán)單醚O普通命名法Diethyl etherDiphenyl etherOOisobutyl secbutyl e

3、thermethyl ethyl ether甲基乙基醚異仲醚O定主鏈OIU P A C2OO 31書寫1,2-dimethoxyene1,2-二甲氧基乙烷OOOmethoxyenecyclopentyloxybenzene3-methoxyprop-1-eneOHOHOHOOCH3OH4,6-dimethoxyhexan e-1,2,3,5-tetraol多羥基化合物醚名法OCH3OCH3glycol methyl etherOH乙二醇一甲醚glycenol-1-methyl etherOHOCH3丙三醇-1-甲醚OHglycol dimethyl etherOCH3乙二醇二甲醚OCH3OHg

4、lycenol-1,2-methyl etherglycenol-2-methyl ether丙三醇-2-甲醚OCH3OCH3丙三醇-1,2-二甲醚OHOH(B) 環(huán)醚（環(huán)氧化物）：“環(huán)氧某烴”oxirane環(huán)氧乙烷OCH31,2-環(huán)氧丙烷1,2-epoxypropaneOCH2Cl3-氯-1,2-環(huán)氧丙烷3-chloro-1,2-epoxypropaneOO1,3-環(huán)氧丙烷1,3-epoxypropane1,4-環(huán)氧丁烷1,4-epoxybutaneOOOtetrahydrofuranO1,4-dioxane1,4-二氧六環(huán)氫呋喃四Crown ether冠醚OOOOOOOOOOOOm-cro

5、wn-nx: the total number of atoms環(huán)的總原子數(shù)y: the number of oxygen atoms環(huán)中的氧原子數(shù)he ringm-冠-nOO12-crown-412-冠-4OOOOO18-crown-618-冠-6OOO11.2Physical and Spectral properties11.2.1Physical properties醚分子間不形成氫鍵，但可與水分子形成氫鍵非直線型：極性分子大，閃點(diǎn)低乙醚可作為麻醉劑11.2.1Spectroscopic data11.3Chemical reactions11.3.111.3.211.3.3Auto

6、oxidation BasicityEther bond cleavage11.3.4 Claisen rearrangement11.3.1Auto oxidation自動(dòng)氧化polymerizeOOO2OOnOHHO氫過氧化乙醚過氧化乙醚（性極強(qiáng)）過氧化物的鑒別：1，淀粉碘化鉀試劑Starch iodide pr2，硫酸亞鐵化鉀試劑處理： 蒸餾前先加入5FeSO4洗至無過氧化物預(yù)防： 加入對(duì)苯二酚或二乙基氨基二硫代甲酸鈉11.3.2Basicity堿性H OH+iceOORRRRRR常用于分離提純醚形成“好”的離去基團(tuán)Ability to form oxonium形成钅羊鹽的能力ROOOR

7、ArRArAr11.3.3Ether bond cleavage醚鍵斷裂ReactionHXORX+ROHRRHXRXMechanism1o R SN2H OX-HXOCH3X+CH3OHH CCHH CCH3333HXCH3X3o RSN1H OOHX+HOCH3HXHXXCH3XReactivity1）氫鹵酸使醚鏈斷裂能力HI HBr HCl常用試劑：57 HI 或 KI + H3PO42）碳氧鍵斷裂順序三級(jí)烷基 二級(jí)烷基 X一級(jí)烷基苯基O1mol HI+HOCH3HICH3XOOH1mol HIICH3+IHI3）環(huán)醚HIHIOHIIIORRRHBrO+BrOHHOBr4）芐基醚在催化加

8、氫條件下氫解H2 / Pd /C OROH+R11.3.4 Claisen rearrangement重排ReactionOH3O1223132OH1O132遷移到鄰位，如果兩個(gè)鄰位均被占據(jù)，則遷移到對(duì)位。MechanismaaabbbOOOcc cHabOHc協(xié)同過程acOObcabOHOcabcHabExles1122OOH3RR 3OH13OR2321R反應(yīng)特征：aabbOHOcc反應(yīng)的：bbacacOO反應(yīng)的推廣：OOaObcHaObc11.4PreparationWilliamson法RONa+RXRO-R+NaXRONa+ROSO3HRO-R+NaOSO3H醇分子間失水烯烴加醇11

9、.5 Epoxides環(huán)氧化物11.5.1Epoxide and its derivatives環(huán)氧化物及其衍生物(A).PreparationO2, AgO250oCRRCOOOHR+RCOOHOOHNaOH, H2OOBrStereochemistryOHONaOHOHH2OBrBrBrO反式共平面BrR HHRHNaOHRH2ORHOOH(B). Ring opening 開環(huán)反應(yīng)1.Acid catalyzed ring opening酸催化開環(huán)RHHHRHHHH+O HOHNuRHHNu:HHRHOHO HSN2反應(yīng)，但是具有SN1反應(yīng)的性質(zhì)。ExlesOHH+H2OOHOOCH3H

10、+CH3OHOHOC6H5H+C6H5OHOHXH+HXOHCNH+HCNOHHOBH2OBH2H+B2H6OOOH2OBOOH2.Base catalyzed ring opening：堿催化開環(huán)試劑一般為堿，活潑，親核力強(qiáng)。Nu:Nu:HRNuRHRHHHHHHOHOO進(jìn)攻方向：空間位阻較小的碳即取代基較少的碳原子ExlesRMgXArOROArOHOHRHROOHHHOROHOOHOHNH3NH2RNHNHR2OHOHRHLiAlH4HHAlH Li3OOH2OAlLi+LiAlO2OOH4(C) Usage用途：雙官能團(tuán)化合物工業(yè)上：制乙二醇OHH+H2OOHO制聚乙二醇H2Ol4HO(CH CH O) Hn22nO制非離子表面活性劑RONaRO(CH2CH2O)nH+nO11.5.2Crown ether冠醚(A). PreparationOClHOOOOORON