1、Exercise1. Give IUPAC name for the following compounds: (CH3)3CCH2CH2CHCH3CH3CH3CH(CH3)22,2,5-Trimethylhexane1-Isopropyl-2-methylcyclohexane2. Draw structures corresponding to the following IUPAC name: 3-Ethyl-4,4-dimethylheptaneExerciseCis-Trans Isomerism (順反異構(gòu)順反異構(gòu)) in Cycloalkanes The common ring

2、size (C3 , C4 , C5, , C6 , C7) are severely restricted in their molecular motation.H3CHCH3HH3CHHCH3Cis-Trans isomers:cis-isomertrans-isomerRotate Cis-Trans isomers are called stereoisomers (立體異構(gòu)立體異構(gòu)), which have their atoms connected in the same order but differ in three-dimensional orientation (空間取

3、向空間取向). P55-57Structures of Alkanes and CycloalkanesOn the same sideOn the opposite sideStructures of Alkanes and CycloalkanesH3CCH3HHcis-1,4-DimethylcyclohexaneH3CHCH3HStructures of Alkanes and Cycloalkanes4. Conformational Isomer（構(gòu)象異構(gòu)體構(gòu)象異構(gòu)體）Conformations：The different arrangements of atoms that re

4、sult from rotation about a single bond are called conformations.Conformer: a specific conformation is called a conformational isomer.構(gòu)象構(gòu)象構(gòu)象異構(gòu)構(gòu)象異構(gòu)P50-51HHHHHH交叉式 (Staggered) 構(gòu)象HHHHHH重疊式 (Eclipsed) 構(gòu)象鋸鋸架架式式(Sawhorse representation)HHHHHHHHHHHH紐紐曼曼投投影影式式(Newman projection)交叉式 (Staggered) 構(gòu)象重疊式 (Eclipse

5、d) 構(gòu)象Structures of Alkanes and Cycloalkanes1). Conformations of Ethane （乙烷的構(gòu)象乙烷的構(gòu)象）H3CCH3Front carbonBack carbonConformational Analysis of EthaneStructures of Alkanes and Cycloalkanes=Stability: Staggered（交叉式交叉式 ） Eclipsed（重疊式重疊式 ） torsional strain 扭轉(zhuǎn)張力扭轉(zhuǎn)張力Structures of Alkanes and Cycloalkanes2). C

6、onformations of Butane（丁烷的構(gòu)象丁烷的構(gòu)象）Conformational Analysis of ButaneStability: 對位交叉式對位交叉式 鄰位交叉式鄰位交叉式 部分重疊式部分重疊式 全重疊式全重疊式 Structures of Alkanes and Cycloalkanes3). Conformations of Cyclohexane（環(huán)己烷的構(gòu)象環(huán)己烷的構(gòu)象） Substituted cyclohexanes are the most common cycloalkanes because of their wide occurrence in n

7、ature. For example：HOCholesterol (膽固醇膽固醇)Structures of Alkanes and Cycloalkanes Chair conformation and boat conformation are two different conformations of cyclohexane.a.角張力角張力 (angle strain)b.扭轉(zhuǎn)張力扭轉(zhuǎn)張力( torsional strain)c.空間張力空間張力 (steric strain)a.角張力角張力 (angle strain)b.扭轉(zhuǎn)張力扭轉(zhuǎn)張力( torsional strain)c.

8、空間張力空間張力 (steric strain)Structures of Alkanes and CycloalkanesAxial and equatorial bonds in cyclohexane+six axial (軸的軸的)hydrogens that are perpendicular (垂直的垂直的) to the ringaxial bonds alternate up-downsix equatorial(赤道的赤道的) hydrogens that are inthe rough plane of the ringequatorial bonds alternate

9、between sides around the ring Structures of Alkanes and Cycloalkanesa bondse bonds One chair conformation can readily interconvert to another chair conformation. The energy barrier to this interconversion is only about 45kJ/mol. This inter- conversion of chair conformations results in the exchange o

10、f axial and equatorial positions.135246123456Ring flipRing flipStructures of Alkanes and Cycloalkanes4). Conformations of substituted cyclohexanesCH3C(CH3)395%100%Structures of Alkanes and CycloalkanesStructures of Alkanes and CycloalkanesDraw the most stable conformation of: 1) 4-tert-Butyl-1-methy

11、lcyclohexane123456CH3(CH3)3C123456Structures of Alkanes and CycloalkanesDraw the most stable conformation of: 2) Cis -4-tert-Butyl-1-methylcyclohexane123456(CH3)3C(CH3)3CCH3Structures of Alkanes and CycloalkanesReview1. Sight along the C2-C3 bond of butane, draw the Newman projection of the most sta

12、ble and least stable conformationsCH3HHCH3HHHH3CHCH3HHmost stableleast stableStaggered (交叉式交叉式)Eclipsed (重疊式重疊式)ReviewName the following compound and draw the most stable conformation of it. CH3CH3C(CH3)3123456(CH3)3CCH3CH312344-tert-Butyl-1,2-dimethylcyclohexaneGeneral Formulas of Alkanes and Cyclo

13、alkanesStructures of Alkanes and Cycloalkanes.Chapter Two Saturated Hydrocarbons: Alkanes and CycloalkanesAlkanes and Cycloalkanes Physical Properties (物理性質(zhì)物理性質(zhì)) of Alkanes and Cycloalkanes Nomenclature of Alkanes and Cycloalkanes.Constitutional Isomers of Alkanes and Cycloalkanes Chemical Propertie

14、s of Alkanes and CycloalkanesSynthesis of Alkanes and CycloalkanesPhysical Properties of Alkanes and Cycloalkanes The physical properties of alkanes due to the presence of weak dispersion force (色散力色散力) between the molecules.Boiling Points (沸點(diǎn)沸點(diǎn)):1) show a regular increase with increasing molecular

15、weight.碳原子數(shù)目碳原子數(shù)目 數(shù)目數(shù)目，b.p2) Increased branching lowers an alkanes boiling point.碳原子數(shù)目相同碳原子數(shù)目相同支鏈支鏈，b.pThe order of boiling point: 1234(分子量分子量)Density (密度密度):Physical Properties of Alkanes and Cycloalkanes As a class, the alkanes and cycloalkanes are the least density of all groups of organic compou

16、nds, Secondary HPrimary HCH3CHCH3CH3Br2hvCl2hv1 %99 %CH3CHCH2BrCH3CH3CBrCH3CH364 %36 %CH3CHCH2ClCH3CH3CClCH3CH3Chapter Two Saturated Hydrocarbons: Alkanes and CycloalkanesSelectivity( 選擇性選擇性) of Halogens: I2 Br2 Cl2 F2Reactivity of Halogens: F2 Cl2 Br2 I2Chapter Two Saturated Hydrocarbons: Alkanes a

17、nd CycloalkanesConclusion: A.Reactivity of Hydrogen: Tertiary H Secondary H Primary HB.Reactivity of Halogens: F2 Cl2 Br2 I2C.Selectivity of Halogens: I2 Br2 Cl2 F2 D. Stability of free radical:CH3hvBr2CH3Br2。1。CCCH33。CChapter Two Saturated Hydrocarbons: Alkanes and Cycloalkanes Among all the isomer

18、s of C5H12 or C8H18, which molecular structure of alkanes does radical chlorination give a single monochloro product?CCH3CH3H3CCH3CCH3CH3CCH3CH3CH3CH3C5H12C8H18CCH3CH2ClH3CCH3CCH3CH3CCH3CH3CH2ClCH3Exercise2. Oxidation of Alkanes and CycloalkanesChapter Two Saturated Hydrocarbons: Alkanes and Cycloal

19、kanesCH4 + 2O2 CO2 + H2OH=-891 kJ / mol燃燃燒燒+CO2+H2OH=-3954 kJ / mol9O23. Isomeration (異構(gòu)化異構(gòu)化) of Alkanes and CycloalkanesCH3CH2CH2CH3Cat.CH3CHCH3CH3CH2CH3AlCl3CH3AlCl3CH3CH3+CH3CH34. Addition of small cycloalkanesChapter Two Saturated Hydrocarbons: Alkanes and Cycloalkanes+H2Ni 200oC 80oCCH3CH2CH3+H

20、2NiCH3CH2CH2CH3 300oC+H2NiCH3CH2CH2CH2CH3Difficult !a. Addition of Hydrogenb. Addition of Bromine (Br2)+Br2RTBrCH2CH2CH2Br+Br2BrCH2CH2CH2CH2BrChapter Two Saturated Hydrocarbons: Alkanes and Cycloalkanesc. Addition of Hydrogen Halide(鹵代烴鹵代烴) HBrBr環(huán)的破裂發(fā)生在環(huán)的破裂發(fā)生在含氫最多和含氫最少含氫最多和含氫最少的兩個碳原子之間的兩個碳原子之間 鹵化氫的加

21、成時，鹵化氫的加成時，氫加在含氫多的碳原子上，氫加在含氫多的碳原子上，鹵素加在鹵素加在含氫少的碳原子上含氫少的碳原子上 HBrBrChapter Two Saturated Hydrocarbons: Alkanes and CycloalkanesHomework for this chapter:P49 Problem 2.9, 2.10P70 Problem 2.46P72 Problem 2.63Demand: The title of the problems should be written in your textbook.Chapter Two Saturated Hydro

22、carbons: Alkanes and CycloalkanesAdditional problem:1. Draw the most stable chair conformation of the following molecules, (a) trans-1- Chloro-3-methylcyclohexane(b) cis-1-Ethyl-2-methylcyclohexane(c) cis-1-Bromo-4-ethylcyclohexane(d) cis-1-tert-Butyl-4-ethylcyclohexane2. Despite the limitations of

23、radical chlorination of alkanes, the reaction is still useful for synthesizing certain halogenated compounds. For which of the following compounds does radical chlorination give a single monochloro product?Chapter Two Saturated Hydrocarbons: Alkanes and Cycloalkanes(a)C2H6(b)CH3CH2CH3(c)(CH3 )3C CH2CH3(d)(e)CH3(f)CCH3CCH3spiral cycloalkanesNomenclature of Alkanes and Cycloalkanesb). Nomenclature of s