Chapter 4 Cycloalkanes环烷烃

Cycloalkanes

第四章环烷烃

Organic Chemistry A (1)

By Prof. Li Yan-Mei

Tsinghua University

Content

4.1 Classification, Isomerization and nomenclature

4.2 Structure of cycloalkanes

4.3 Physical properties & spectrum data

4.4 Chemical properties

4.5 Preparation (learn on your own)

4.1 Classification, Isomerization and nomenclature

4.1.1 Classification

4.1.2 Isomerism

4.1.3 Nomenclature

4.1.1 Classification

By the size of the ring 按环的大小

Small rings Medium rings

Common rings

Large rings

C3~C4

C8~C12

C5~C7

C13~

By the saturation 按不饱和度

C n H2n C n H2n-2 C n H2n-4Cycloalkanes 环烷Cyclo olefines 环烯Cyclo alkynes 环炔

Monocyclic compounds 单环

By the number of the rings 按环的数目

Polyring compounds 多环

Fused ring 稠环Bridged ring 桥环Spiro rings 螺环

两环之间共用一个碳原子两环之间共用一根共

价键（共用两个直接

相连的碳原子）

两环之间共用两个

不直接相连的碳原

子

螺原子

桥头碳

几环？

To define the number of the rings:

The number of cutting you need to get a chain molecule out of a poly ring compound

将桥（稠）环烃变为链状化合物时需要断裂的碳链

数。如需断裂两次，则为二环化合物，断裂三次则

为三环化合物。

Some interesting bridging compounds

Cubane 立方烷

Primane

棱烷

Diamentane

金刚烷

篮烷

4.1.2 Isomerism

Constitutional isomers are derivated from

the change of size of rings and length of

side chains

C5H10

环的大小及侧链长短与位置变化

4.1.3 Nomenclature 命名

4.1.3.1 Monocyclic alkane 单环烷烃

1, When the side chain is not very complicate: 当支链不复杂时，以环烷烃为母体

methylcyclopentane

2-ethyl-4-methyl-1-propylcycloheptane

1-ethyl-3-methylcyclopentane

1,2-dimethylcyclopentane

1,2-二甲基环戊烷

甲基环戊烷

1-甲基-3-乙基环戊烷

4-甲基-3-乙基-1-丙基环己烷

2, When the side chain is complicate or difficult to name:当支链较复杂或不易命名时，以环烷基为取代基

3-cyclohexylhexane

3-环己基己烷

3, When two rings are connected 两环相连时

Cyclopropylcyclohexane 环丙基环己烷Cyclopropylcyclopropane

环丙基环丙烷

4, Cis and trans isomerism:

CH 3CH 3H

H

CH 3H CH 3

H

CH 3CH 3

CH 3

CH 3

Cis-1,4-dimethylcyclohexane

Trans-1,4-dimethylcyclohexane

CH3

CH3

CH3

How to name this compound ?

4.1.3.2 Polyring alkane 多环烷烃

1, Spiro cycloalkanes 螺环烃

1）选母体：根据成环的总碳原子数，称为“螺某烷”。2）编号：从小环开始；从第一个非螺原子开始。3）书写：先写词头“螺”

方括号内沿着编号方向写出每个环中除螺原子

外的每个环的碳原子数

数字之间用圆点隔开

最后写出包括螺原子在内碳原子数的烷烃名称 1

23

4

5

6

789

10螺[4.5]癸烷

1