《环烷烃的命名12.ppt》由会员分享，可在线阅读，更多相关《环烷烃的命名12.ppt（40页珍藏版）》请在三一文库上搜索。
1、,1. 环状化合物顺反构型的确定 由于成环碳原子的单键不能自由旋转，因此当环上带有两个或多个基团时，就会产生两个或多个立体异构体。一个异构体的两个取代基团在环的同侧称为顺式构型（cis configuration）。另一个异构体的两个取代基在环的异侧，称为反式构型（trans configuration）。例如：,一、环烷烃的命名,2. 单环烷烃的命名 只有一个环的环烷烃称为单环烷烃（monocyclic alkane）。环上没有取代基的环烷烃命名时只须在相应的烷烃前加环，英文名称只须在相应的英文名称前加cyclo。例如：,环上有取代基的单环烷烃命名分两种情况。环上的取代基比较复杂时，应将链作
2、为母体，将环作为取代基，按链烷烃的命名原则和命名方法来命名。例如：,而当环上的取代基比较简单时，通常将环作为母体来命名。例如：,当环上有两个或多个取代基时，要对母体环进行编号，编号仍遵守最低系列原则。例如：,但由于环没有端基，有时会出现有几种编号方式都符合最低系列原则的情况。例如：,上面列出了同一个化合物的三种编号方式，它们都符合最低系列原则。也即应用最低系列原则无法确定哪一种编号优先。 中文命名时，应让顺序规则中较小的基团位次尽可能小。取（i）的编号 1,3二甲基5乙基环己烷。 英文命名时，按英文字母顺序，让字母排在前面的基团位次尽可能小。取（iii）的编号 lethyl3,5dimethy
3、lcyclohexane。,环上带有三个或更多基团时，若用顺、反表示构型，要选用一个参照基团，通常选用1位的基团为参照基团，用r1表示，放在名称的最前面。例如：,环上带有双键或者三键时，将双键的两个碳的位次标为C1和C2，第一个取代基的位次尽可能低，不必标出双键的位次。例如：,将环作为取代基时，如果环上带有双键或者三键时，则需要将双键的两个碳的位次标出并尽可能低。例如：,二、芳香烃的命名,1 含苯基的单环芳烃的命名 2 多环芳烃的命名 3 非苯芳烃的命名,1 含苯基的单环芳烃的命名 最简单的此类单环芳烃是苯（benzene）。其它的这类单环芳烃可以看作是苯的一元或多元烃基的取代物。苯的一元烃基
4、取代物只有一种。命名的方法有两种，一种是将苯作为母体。烃基作为取代基，称为苯。另一种是将苯作为取代基，称为苯基（phenyl），它是苯分子减去一个氢原子后剩下的基团，可简写成ph，苯环以外的部分作为母体，称为苯（基）。例如：,苯的二元烃基取代物有三种异构体，它们是由于取代基团在苯环上的相对位置的不同而引起的，命名时用邻或o（ortho）表示两个取代基处于邻位，用间或m（meta）表示两个取代基团处于中间相隔一个碳原子的两个碳上，用对或p（para）表示两个取代基团处于对角位置，邻、间、对也可用1,2、1,3、1,4表示。例如：,若苯环上有三个相同的取代基，常用“连”（英文用“vicinal”，
5、简写“vic”）为词头，表示三个基团处在1,2,3位。用“偏”（英文用“unsymmetrical”，简写“unsym”）为词头，表示三个基团处在1,2,4位。用“均”（英文用“symmetrical”，简写“syn”）为词头，表示三个基团处在1,3,5位。例如：,当苯环上有两个或多个取代基时，苯环上的编号应符合最低系列原则。而当应用最低系列原则无法确定那一种编号优先时，与单环烷烃的情况一样，中文命名时应让顺序规则中较小的基团位次尽可能小，英文命名时，应按英文字母顺序，让字母排在前面的基团位次尽可能小。例如：,除苯外，下面六个芳香烃的俗名也可作为母体化合物的名称。而其它芳烃化合物可看作它们的衍
6、生物。,2 多环芳烃的命名 分子中含有多个苯环的烃称为多环芳烃（polycyclic arenes）。主要有多苯代脂烃（multi-phenyl alicyclic hydrocarbons）、联苯（biphenyl）和稠合多环芳烃（fused polycyclic arenes）。 （1） 多苯代脂烃的命名 链烃分子中的氢被两个或多个苯基取代的化合物称为多苯代脂烃。命名时，一般是将苯基作为取代基，链烃作为母体。例如：,（2）联苯型化合物的命名 两个或多个苯环以单键直接相连的化合物称为联苯型化合物。例如：,联苯类化合物的编号总是从苯环和单键的直接连接处开始，第二个苯环上的号码分别加上（ ）符号
7、，第三个苯环上的号码分别加上“ ”符号，其它依次类推。苯环上如有取代基，编号的方向应使取代基位置尽可能小，命名时以联苯为母体。例如：,（3）稠环芳烃的命名 两个或多个苯环共用两个邻位碳原子的化合物称为稠环芳烃。最简单最重要的稠环芳烃是萘、蒽、菲。,萘、蒽、菲的编号都是固定的，如上所示。,萘分子的1,4,5,8位是等同的位置，称为位，2,3,6,7位也是等同的位置，称为位。蒽分子的1,4,5,8位等同，也称为位，2,3,6,7位等同，也称为位，9,10位等同，称为位。菲有五对等同的位置，它们分别是：1,8，2,7，3,6，4,5和9,10。取代稠环芳烃的名称格式与有机化合物名称的基本格式一致。例
8、如：,3 桥环烷烃的命名 桥环烷烃（bridged hydrocarbon）是指共用两个或两个以上碳原子的多环烷烃。 共用的碳原子称为桥头碳（bridgehead carbon），两个桥头碳之间可以是碳链，也可以是一个键，称为桥。 将桥环烃变为链形化合物时，要断裂碳链，如需断两次的桥环烃称为二环（bicyclo），断三次的称三环（tricyclo）等等，然后将桥头碳之间的碳原子数（不包括桥头碳）由多到少顺序列在方括弧内，数字之间在右下角用圆点隔开，最后写上包括桥头碳在内的桥环烃碳原子总数的烷烃的名称。 如桥环烃上有取代基，则列在整个名称的前面，桥环烃的编号是从第一个桥头碳开始，从最长的桥编到第
9、二个桥头碳，再沿次长的桥回到第一个桥头碳，再按桥渐短的次序将其余的桥编号，如编号可以选择，则使取代基的位号尽可能最小：,如上式三环烃中，在2,6位中间无碳原子，因此用零表示，在零的右上角标明位号，位号中间用逗号隔开。,对于一些结构复杂的桥环烷烃，常用俗名。,4 螺环烷烃的命名 螺环烷烃（spirocyclic hydrocarbon）是指单环之间共用一个碳原子的多环烃，共用的碳原子称为螺原子（spiro atom）。螺环的编号是从螺原子上的小环开始顺序编号，由第一个环顺序编到第二个环，命名时先写词头螺，再在方括弧内按编号顺序写出除螺原子外的环碳原子数，数字之间用圆点隔开，最后写出包括螺原子在内
10、的碳原子数的烷烃名称，如有取代基，在编号时应使取代基位号最小，取代基位号及名称列在整个名称的最前面：,螺5.5十一烷分子对称，可合并命名，称为螺二环己烷（spirobicyclohexane）。,The names of saturated monocyclic hydrocarbons (with no side chains)are formed by attaching the prefix cyclo to the name of the acyclic saturated unbranched hydrocarbon with the same number of carbon at
11、oms. The generic name of saturated monocyclic hydrocarbons (with or without side chains) is cycloalkane . Exa. cyclopropane, cyclohexane. Univalent radicals derived from cycloalkanes (with no side chains) are named by replacing the ending-ane of the hydrocarbon name by -yl, the carbon atom with the
12、free valence being numbered as l. The generic name of these radicals is cycloalkyl. Exa. Cyclopropyl, cyclohexyl.,The names of unsaturated monocyclic hydrocarbons (with no side chains) are formed by substituting-ene. -adiene,-atriene,-yne“, -adiyne, etc., for -ane in the name of the corresponding cy
13、cloalkane. The double and triple bonds are given numbers as low as possible. Exa. Cyclohexane, 1. 3-cyclohexadiene.,The following names for monocyclic aromatic hydrocarbons are retained: benzene, toluene, xylene, mesitylene, cumene, styrene, etc.,The names of univalent radicals derived from unsatura
14、ted monocyclic hydrocarbons have the endings-enyl, -ynyl, -dienyl, etc. The carbon atom with the free valence is numbered as 1. Exa. 2-cyclopenten-1-yl, 2,4-cyclopentadien-1-yl.,The following trivial names for radicals having a single free valence are retained: phenyl, tolyl, xylyl, mesityl, cumenyl
15、, benzyl, styryl, etc. Since the name phenylene (o-, m-, or p-) is retained for the radical -C6H4-, bivalent radicals formed from substituted benzene derivatives and having the free valences at ring atoms are named as substituted phenylene radicals. The carbon atoms having the free valences are numb
16、ered 1, 2-, 1, 3-, or 1,4- as appropriate.,The names of polycyclic hydrocarbons with maximum number of non-cumulative double bonds end in -ene. The following list contains the names of polycyclic hydrocarbons which are retained, such as naphthalene, anthracene, phenanthrene, indene etc. The names of
17、 ortho-fused or ortho- and peri-fused polycyclic hydrogenated hydrocarbons with less than maximum number of non-cumulative double bonds are formed from a prefix dihydro-, tetrahydro-,etc. , followed by the name of the corresponding unreduced hydrocarbon. The prefix perhydro- signifies full hydrogena
18、tion. Exa. 1,4-dihydronaphthalene, tetradecahydroanthracene or perhydroanthracene.,Univalent radicals derived from ortho-fused or ortho- and peri-fused polycyclic hydrocarbons with names ending in -ene by removal of a hydrogen atom from an aromatic or alicyclic ring are named in principle by changin
19、g the ending-ene of the names of the hydrocarbons to-enyl. Examples : 2-indenyl. Exceptions: naphthyl , anthryl , phenanthryl.,Bicyclic Bridged Hydrocarbons Saturated alicyclic hydrocarbon systems consisting of two rings only, having two or more atoms in common, take the name of an open chain hydroc
20、arbon containing the same total number of carbon atoms preceded by the prefix bicyclo-. The number of carbon atoms in each of the three bridges connecting the two tertiary carbon atoms is indicated in brackets in descending order. The system is numbered commencing with one of the bridgeheads, number
21、ing proceeding by the longest possible path to the second bridgehead; numbering is then continued from this atom by the longer unnumbered path back to the first bridgehead and is completed by the shortest path from the atom next to the first bridgehead.,Radicals derived from bridged hydrocarbons are
22、 named by replacing the ending ane of respective bridged hydrocarbon name by yl. The numbering of the hydrocarbon is retained and the point or points of attachment are given numbers as low as is consistent with the fixed numbering of the saturated hydrocarbon. Polycyclic Systems Cyclic hydrocarbon s
23、ystems consisting of three or more rings may be named in accordance with the naming principles stated in bicyclic system. The appropriate prefix tricyclo- tetracyclo-”, etc. , is substituted for bicyclo- before the name of the open-chain hydrocarbon containing the same total number of carbon atoms.
24、Radicals derived from these hydrocarbons are named according to the naming principles set forth in radicals derived from bridged hydrocarbons.,When there is a choice, the following criteria are considered in turn, until a decision is made: (a)The main ring shall contain as many carbon atoms as possi
25、ble, two of which must serve as bridgeheads for the main bridge. (b)The main bridge shall be as large as possible. (c)The main ring shall be divided as symmetrically as possible by the main bridge. (d)The superscripts locating the other bridges shall be as small as possible.,Hydrocarbon Bridges Poly
26、cyclic hydrocarbon systems which can be regarded as ortho-fused or ortho- and peri-fused systems and which, at the same time, have other bridges, are first named as ortho-fused or ortho- and peri-fused systems. The other bridges are then indicated by prefixes derived from the name of the corresponding hydrocarbon by replacing the final-ane,-ene, etc., by -ano, -eno, etc., and their positions are indicated by the points of attachment in the parent compound. If bridges of different types are present, they are cited in alphabetical order.,