大二有机第二章

1、General Formulas of Alkanes and CycloalkanesStructures of Alkanes and CycloalkanesChapter Two Saturated Hydrocarbons: Alkanes and CycloalkanesAlkanes and Cycloalkanes (烷烃和环烷烃) Physical Properties of Alkanes and Cycloalkanes Nomenclature (命名) of Alkanes and CycloalkanesConstitutional Isomers of Alkan

2、es and Cycloalkanes Chemical Properties of Alkanes and CycloalkanesSynthesis of Alkanes and CycloalkanesAlkanes and CycloalkanesHydrocarbons (烃): are compounds whose molecules contain only carbon and hydrogen atoms. 烃类化合物 (Hydrocarbons)脂肪族 (Aliphatic)芳香族 (Aromatic) 烷烃Alkanes 烯烃Alkenes 炔烃Alkynes脂环烃Cy

3、clic Aliphatic 环烷烃Cycloalkanes 环烯烃CycloalkenesAlkanes and CycloalkanesCycloalkanes: are alkanes in which all or some of the carbon atoms are arranged in ring.环烷烃全部或部分碳原子成环状排列的烷烃。 Alkanes (Saturated Hydrocarbons): Those hydrocarbons in which all of the carbon- carbon bonds are single bonds.烷烃环烷烃烷烃分子中

4、的碳原子均以单键相连的烃。General Formulas(通式) of Alkanes and CycloalkanesStructures of Alkanes and Cycloalkanes.Chapter Two Saturated Hydrocarbons: Alkanes and CycloalkanesAlkanes and Cycloalkanes Physical Properties of Alkanes and Cycloalkanes Nomenclature of Alkanes and Cycloalkanes.Constitutional Isomers of

5、Alkanes and Cycloalkanes Chemical Properties of Alkanes and CycloalkanesSynthesis of Alkanes and CycloalkanesGeneral Formulas of Alkanes and CycloalkanesAlkanes have the general formula: CnH2n+2, where n is an integer (整数). a. Alkane (烷烃)CH4、CH3CH3、CH3CH2CH3 、CH3CH2CH2CH3b. Cycloalkane (环烷烃) CnH2nGe

6、neral Formulas of Alkanes and CycloalkanesStructures of Alkanes and Cycloalkanes.Chapter Two Saturated Hydrocarbons: Alkanes and CycloalkanesAlkanes and Cycloalkanes Physical Properties of Alkanes and Cycloalkanes Nomenclature of Alkanes and Cycloalkanes.Constitutional Isomers (构造异构) of Alkanes and

7、Cycloalkanes Chemical Properties of Alkanes and CycloalkanesSynthesis of Alkanes and Cycloalkanes a. Alkane (烷烃)Constitutional Isomers of Alkanes and CycloalkanesC4H10: are compounds that have the same numbers and kinds of atoms but differ in the way the atoms are arranged (原子的排列方式不同).Isomers(同分异构体)

8、: are compounds that have their atoms connected in different orders (原子的连接次序不同).Constitutional isomers(构造异构体):P41-42Constitutional isomers (构造异构体) may have: Constitutional Isomers of Alkanes and Cycloalkanesa. different carbon skeletons (不同的碳骨架):b. different functional groups (不同的官能团):c. different l

9、ocations of a functional group along the chain (官能团的位置不同):Constitutional Isomers of Alkanes and Cycloalkanes Constitutional isomers of alkanes:b. Cycloalkane (环烷烃) Constitutional Isomers of Alkanes and Cycloalkanes How many constitutional isomers of C5H10 are there in cycloalkanes?Isomerism is one o

10、f the reasons for the larger number of organic compounds.Constitutional isomerismThe size of the ringThe length and locations of the branch chainGeneral Formulas of Alkanes and CycloalkanesStructures of Alkanes and CycloalkanesChapter Two Saturated Hydrocarbons: Alkanes and CycloalkanesAlkanes and C

11、ycloalkanes Physical Properties of Alkanes and Cycloalkanes Nomenclature (命名) of Alkanes and CycloalkanesConstitutional Isomers of Alkanes and Cycloalkanes Chemical Properties of Alkanes and CycloalkanesSynthesis of Alkanes and CycloalkanesNomenclature of Alkanes and Cycloalkanes The International U

12、nion of Pure and Applied Chemistry (IUPAC) systemPrefix+Parent+SuffixWhere are the substituents (取代基) and functional group?How many carbons?What family?国际纯粹化学和应用化学联合会Nomenclature of Alkanes and Cycloalkanes1. IUPAC System Applied for Nomenclature of Alkanea. Naming the Unbranched Alkanes (直链烷烃):Pref

13、ix+Parent+SuffixHow many carbons?aneP43Nomenclature of Alkanes and Cycloalkanes Name Number of Carbon Atoms StructureMeth + ane 1 CH4Eth + ane 2 CH3CH3Prop + ane 3 CH3CH2CH3But + ane 4 CH3CH2CH2CH3Pent + ane 5 CH3(CH2)3CH3Hex + ane 6 CH3(CH2)4CH3Hept + ane 7 CH3(CH2)5CH3Oct + ane 8 CH3(CH2)6CH3Non +

14、 ane 9 CH3(CH2)7CH3Dec + ane 10 CH3(CH2)8CH3Undec + ane 11 CH3(CH2)9CH3Dodec + ane 12 CH3(CH2)10CH3Tridec + ane 13 CH3(CH2)11CH3 Nomenclature of Alkanes and Cycloalkanes123456 Hex aneNomenclature of Alkanes and Cycloalkanesb. Naming the branched Alkanes (带支链烷烃):a). The degrees of carbon and hydrogen

15、:Primary carbon (伯碳，一级碳，1oC)1oH, 伯氢Secondary carbon (仲碳，二级碳，2oC)2oH, 仲氢Tertiary carbon (叔碳，三级碳，3oC)3oH, 叔氢Quaternary carbon (季碳，四级碳，4oC)？P46P45Nomenclature of Alkanes and Cycloalkanesb). Alkyl Group (烷基) : If a hydrogen atom is removed from an alkane, the partial structure that remains is called an

16、alkyl group (烷基) .Alkane Name Alkyl Group Name (abbreviation)MethaneEthanePropaneButaneMethyl (Me)Ethyl (Et)Propyl (Pr)Butyl (Bu)R-甲基乙基丙基丁基 Alkyl groups are generated not only by removing a hydrogen from an end carbon but also by removing a hydrogen atom from an internal(内部的) carbon.Nomenclature of

17、Alkanes and CycloalkanesIsopropyl (异丙基)Three-carbon alkyl groupPropane (丙烷)Propyl (正丙基)Nomenclature of Alkanes and CycloalkanesFour-carbon alkyl grouptwo isomersButyl (正丁基)sec-Butyl (仲丁基)Isobutyl (异丁基)tert-Butyl (特丁基)s-Butylt-ButylNomenclature of Alkanes and CycloalkanesFive-carbon alkyl groupIsopen

18、tyl (异戊基)Neopentyl (新戊基)tert-Pentyl (叔戊基)Nomenclature of Alkanes and CycloalkanesIUPAC system applied for nomenclature of branched alkanes including the following 3 steps: P46Prefix+Parent+SubffixWhere are the substituents (取代基)and functional group?How many carbons?What family?aneNaming branched alk

19、anes: Nomenclature of Alkanes and CycloalkanesStep1: Find the parent chain（选主链） Find the longest continuous chain (连续的最长链) of carbon atoms present in the molecule, if two different chains of equal length are present, choose the one with the larger number of branch points (取代基最多的) as the parent, and

20、use the name of that chain as the parent name.Step 2: Number the atoms in the parent chain (编序号)Nomenclature of Alkanes and Cycloalkanes Beginning at the end nearer the first branch point (靠近支链较近的一端), number each carbon atom in the parent chain. If there is branching an equal distance away from both

21、 ends of the parent chain, begin numbering at the end nearer the second branch point (较为靠近第二支链一端)。123456789Nomenclature of Alkanes and CycloalkanesStep 3 Write the name as a single word.（用一个词命名）a. Use little line（短横) to separate the different prefixes; b. Use multiplier prefixes di-, tri-, tetra- to

22、 cite identical substituent (相同取代基合并);c. Use commas (逗号) to separate numbers;d. Cite different substituents in alphabetical order (字母顺序);123456789methylethylnonane3- Ethyl- 4,7- dimethyle. The first letter should be capitalized (大写的).Nomenclature of Alkanes and CycloalkanesFor example:123456782,3-Di

23、methyl-6-(2-methylpropyl)decane123456789101234-Ethyl-5-isopropyl-2,6-dimethyloctane6-Isobutyl-2,3-dimethyldecaneMethylMethylEthylisopropylisobutylNomenclature of Alkanes and Cycloalkanes2. IUPAC System Applied for Nomenclature of CycloalkaneCycloalkyl Group (环烷基): If a hydrogen atom is removed from

24、an cycloalkane, the partial structure that remains is called an cycloalkyl group (环烷基). Cyclopropyl Cyclobutyl Cyclopentyl Cyclohexyl 环丙基 环丁基 环戊基 环己基For example:P54-551-Methylcyclohexane3-Cyclopropyl-2-methylhexaneNumbering the alkyl groups on the ring by alphabetical priority Nomenclature of Alkane

25、s and Cycloalkanes1-Ethyl-3-methylcyclohexaneNumbering the second substituent has as low a number as possible, until the third or fourth has. 1232-Ethyl-1,4-dimethylcyclohexane4(排序在前的取代基小的编号)131ReviewNaming the following alkyl group:sec-butylIsobutyltert-ButylIsopropylReviewNaming the following comp

26、ounds:51234674-Ethyl-3-methylheptane12342-Ethyl-1,4-dimethylcycloheptaneGeneral Formulas of Alkanes and CycloalkanesStructures of Alkanes and Cycloalkanes.Chapter Two Saturated Hydrocarbons: Alkanes and CycloalkanesAlkanes and Cycloalkanes Physical Properties of Alkanes and Cycloalkanes Nomenclature

27、 of Alkanes and Cycloalkanes.Constitutional Isomers of Alkanes and Cycloalkanes Chemical Properties of Alkanes and CycloalkanesSynthesis of Alkanes and Cycloalkanes1. sp3 Hybridization (杂化)Structures of Alkanes and CycloalkanesC: 1s22s22px12py12pz0 Hybrid orbital theory was provided in 1931 by Linus

28、 Pauling who showed mathematically how an s orbital and three p orbitals on an atom can combine, or hybridize (杂化) to form equivalent( 等性的) atomic orbitals. P11-13Structures of Alkanes and CycloalkanesA process for obtaining sp3-hybridized carbon atomsthe four hybrid orbitals have a specific geometr

29、y, forming tetrahedron (正四面体) with the bond angle (键角) of each H-C-H is 109.5o.four equivalent( 等性的) atomic orbitals. 1/4 s 和 3/4 p 轨道的成分Structures of Alkanes and Cycloalkanes The four identical orbitals of an sp3 hybridized carbon atom can overlap with the 1s orbital of hydrogen atom head on head t

30、o form C-H bond;Two carbon atoms bond to each other by overlap of an sp3 Hybrid orbital head on head to form C-C bond.Whats the bond ? 2. Structures of AlkanesStructures of Alkanes and Cycloalkanes Such bonds, which are formed by the head-on overlap (头碰头重叠) of two atomic orbitals along a line drawn