By junru wang

1By junru wBy junru wangang

Organic chemistry生物学科生物学科

有机化学教学多媒体课件有机化学教学多媒体课件2006.022006.02

作业 :

P151: 1: (2,3,4,6) 3: (3,4) 4: (3,4)

第 4 章立体化学

Stereochemistry

胰岛素

第四章 Stereochemistry重点讲授内容

一、分子手性与旋光性 Molecular Chirality:Enantiomers二、对称性、手性、手性碳与构型标记三、不含手性碳的旋光活性分子四、光活性物质的物性与旋光性的测定五、反应中的立体化学六、光活性混合物的拆分方法

第一节分子手性与旋光性第一节分子手性与旋光性Molecular Chirality: EnantiomersMolecular Chirality: Enantiomers

第一节分子手性与旋光性第一节分子手性与旋光性Molecular Chirality: EnantiomersMolecular Chirality: Enantiomers

Pharaohs, with two left hands or two right hands—they just didn’t seem to notice.

The ancient Egyptians had less care for the chirality of hands

A molecule is chiral if its two mirror image forms are not superposable upon one another.

A molecule is achiral if its two mirror image forms are superposable..

Chirality

BrBrClCl

HH

FF

Bromochlorofluoromethane is chiral

It cannot be superposed point for point on its mirror image.

BrBrClCl

HH

FF

Bromochlorofluoromethane is chiralBromochlorofluoromethane is chiral

HH

ClClBrBr

FFTo show nonsuperposability, rotate this model 180° around a vertical axis.

BrBrClCl

HH

FF

Bromochlorofluoromethane is chiral

HH

ClClBrBr

FF

Another Another looklook

are enantiomers with respect to each other

andand

nonsuperposable mirror images are called enantiomers

EnantiomersEnantiomers

对映异构：分子式、构造式相同、构型互呈镜像对映关系的立体异构现象

同分异构

构造异构

立体异构

碳架异构位置异构官能团异构构象异构构型异构

顺反异构

对映异构旋光异构

（互变异构）

ChlorodifluoromethaneChlorodifluoromethaneis achiralis achiral

ChlorodifluoromethaneChlorodifluoromethaneis achiralis achiral

The two structures are mirror images, but are not enantiomers, because they can be superposed on each other.

a carbon atom with fourdifferent groups attached to it

also called:chiral centerasymmetric centerstereocenter

The Stereogenic Center

w

x y

z

C

第二节对称性、手性、手性碳与构型标记

对称性与手性手性碳与分子手性手性、对称性与旋光性构型标记

绝对构型相对构型

一、旋光性与分子结构的关系

凡是可具有结构不对称性（无反映对称性）的分子都具有旋光性；最常见的旋光活性物质是含有手性碳的化合物。

对称因素：对称面（）；对称中心 (i)对称性、不对称性与手性 :凡是具有反映对称性的分子称为非手性分子凡是没有反映对称性的分子称为手性分子不对称性：找不到任何一个对称因素的分子手性是不对称性之一种反映对称性———对称分子———无旋光性


对称性与手性 :有对称性的分子一定是非手性分子有手性的分子一定具有非反映应对称性手性碳与手性分子二者关系有手性碳的分子不一定就是手性分子手性分子并不一定就含有手性碳只有一个手性碳的分子一定就是手性分子


手性碳与手性分子二者关系手性分子并不一定就含有手性碳

右手螺旋左手螺旋


手性、对称性与旋光性（ 1 ）有反应对称性的分子：物象重合，

不具有旋光性，是非手性分子（ 2 ）无对称性的分子：物象不重合，有

旋光性，是手性分子构型与旋光性分子结构的不对称性导致，物象不重合；

二者主要差异在于构型不同；

对称因素

手性 (chirality) ：物质的分子与其镜像不能重合

的性质，是产生旋光性的充分和必要条件。

1 、对称面 (Mirror)

反映对称性 : Sn, n1; S1= ; S2=i

A plane of symmetry bisects a molecule into two A plane of symmetry bisects a molecule into two mirror image halves. Chlorodifluoromethane mirror image halves. Chlorodifluoromethane

has a plane of symmetry.has a plane of symmetry.

Plane of symmetryPlane of symmetry

A plane of symmetry bisects a molecule into two mirror image halves.1-Bromo-1-chloro-2-fluoroethene has a planeof symmetry.

Plane of symmetryPlane of symmetry

2 、对称中心

对称中心

A point in the center of theA point in the center of themolecule is a center of molecule is a center of symmetry if a line drawn symmetry if a line drawn from it to some element, from it to some element, when extended an equal when extended an equal distance in the opposite distance in the opposite direction, encounters an direction, encounters an identical element. identical element.

Center of symmetryCenter of symmetry

A point in the center of A point in the center of thethemolecule is a center of molecule is a center of symmetry if a line drawn symmetry if a line drawn from it to any element, from it to any element, when extended an equal when extended an equal distance in the opposite distance in the opposite direction, encounters an direction, encounters an identical element. identical element.

Center of symmetryCenter of symmetry

对称中心

反映对称性 : Sn, n1; S1= ; S2=i

3 、对称轴

对称轴H

HH

Cl H

Cl

H

HCl

H Cl

H

4 、更替对称轴

A molecule with a single stereogenic center is chiral.

Bromochlorofluoromethane is an example.

Chirality and stereogenic centers

ClCl FF

BrBr

HH

CC

A molecule with a single stereogenic center is chiral.

2-Butanol is another example.

CHCH33

OHOH

HH

CC CHCH22CHCH33

Chirality and stereogenic centers

Examples of molecules Examples of molecules with 1 stereogenic centerwith 1 stereogenic center

CHCH33

CC

CHCH22CHCH33

CHCH22CHCH22CHCH22CHCH33CHCH33CHCH22CHCH22

a chiral alkanea chiral alkane


Linalool, a naturally occurring chiral alcoholLinalool, a naturally occurring chiral alcohol

OHOH

Examples of molecules with 1 stereogenic center

1,2-Epoxypropane: a stereogenic centercan be part of a ring

O

H2C CHCH3

attached to the stereogenic center are:—H—CH3

—OCH2

—CH2O


Limonene: a stereogenic centLimonene: a stereogenic center can be part of a ringer can be part of a ring

CHCH33

HH CC

CHCH33

CHCH22

attached to theattached to thestereogenic center are:stereogenic center are:——HH——CHCH22CHCH22

——CHCH22CH=CH=——C=C=


Chiral as a result of isotopic substitutionChiral as a result of isotopic substitution

CHCH33CCDD

TT

HH

二、构型标记 Relative and Absolute Configuration

相对构型绝对构型

ConfigurationConfiguration

相对构型Relative configurationcompares the a

rrangement of atoms in space of one compound with those of another.

until the 1950s, all configurations were relative

绝对构型Absolute configuration is the precise

arrangement of atoms in space. now we can determine the absolute

configuration of almost any compound

1 、相对构型标记 D/L

（ + ）－甘油醛（ - ）－甘油醛 D L

D －（ + ）－甘油醛 L －（ - ）－甘油醛常用来确定糖、氨基酸等构型

CH2OH

H

CHOCHO

CH2OH

HOH OH

相对构型相对构型 (Relative Conformation) (Relative Conformation)

H OH

CHO

CH2OH

HHO

CHO

CH2OH

D - （ + ） - 甘油醛 L - （ + ） - 甘油醛

化学关联法：

H OH

CHO

CH2OH

HgO H OH

COOH

CH2OH

H OH

COOH

CH3

D- （ + ） - 甘油醛 D- （ - ） - 甘油酸 D-（ - ） - 乳酸

2 、绝对构型的标记

1970 IUPAC R/S 标记任何一个手性碳 ( 或手性分子 )

明确与手性碳相连的 4 个不同基团的优先次序用手模型法或透视法判断其构型

H OH

CHO

CH2OH

HHO

CHO

CH2OH

R - （ + ） - 甘油醛 S - （ + ） - 甘油醛

Which is which?

E. Fisher 1891;

1954 x-ray 证实

绝对构型绝对构型 (Absolute Conformation)(Absolute Conformation)

IUPAC(1970) R 、 S 构型系统命名法：

a

c

C

bd

¹Û²ì Õß

a

b

C

cd

¹Û²ì Õß

R-¹¹ ÐÍ S-¹¹ ÐÍ

a>b>c>d

43

2

1

ExampleExample

4 3

2

1

Order of decreasing rank:Order of decreasing rank:44 > > 33 > 2 > > 2 > 11

2.1 含一个手性碳的化合物

43

2

1

ExampleExample

4 3

2

1

Order of decreasing rank:Order of decreasing rank:44 33 2 2

clockwiseclockwiseRR

anticlockwiseanticlockwiseSS

((SS)-2-Butanol)-2-Butanol

CC OHOH

HH33CC

HHCHCH33CHCH22

Enantiomers of 2-butanolEnantiomers of 2-butanol CCHOHO

CHCH33

HHCHCH22CHCH33

((RR)-2-Butanol)-2-Butanol

HHHH33CC

HH

HH

Stereogenic center in a ringStereogenic center in a ring

RR

——CHCH22C=C > —CHC=C > —CH22CHCH2 2 > > —CH—CH33 > —H > —H

Rules for Fischer projectionsRules for Fischer projections

Arrange the molecule so that horizontal bonArrange the molecule so that horizontal bonds at stereogenic center point toward you ands at stereogenic center point toward you and vertical bonds point away from you.d vertical bonds point away from you.

Br Cl

F

H

BrBr ClCl

FF

HH

IbuprofenIbuprofen is chiral, but normally sold as is chiral, but normally sold asa racemic mixture. The a racemic mixture. The SS enantiomer enantiomer is the one responsible for its analgesic is the one responsible for its analgesic and antiinflammatory properties. and antiinflammatory properties.

Chiral drugsChiral drugs

CHCH22CH(CHCH(CH33))22

HHHH33CC

CC

OO

CC

HOHO

What are all the possible R and S combinations of the two stereogenic centers in this molecule?

O

CH3CHCHCOH

HO OH

23

Carbon-2 R R S SCarbon-3 R S R S

4 Combinations = 4 Stereoisomers

2.2 含 2 个手性碳 ( 中心 ) 的化合物2,3-Dihydroxybutanoic acid

enantiomers: 2R,3R and 2S,3S2R,3S and 2S,3R

HOHO

COCO22HH

CHCH33

HH

OHOHHHRR

RR

COCO22HH

CHCH33

HH

HHHOHO

OHOH

SS

SSenantiomersenantiomersenantiomersenantiomers

COCO22HH

HH

CHCH33

HOHO

HHHOHO

RR

SS

diastereomersdiastereomersdiastereomersdiastereomersCOCO22HH

CHCH33

HH OHOH

OHOHHHRR

SS

enantiomersenantiomersenantiomersenantiomers

[[] = -9.5°] = -9.5° [[] = +9.5°] = +9.5°

[[] = -17.8°] = -17.8°[[] = +17.8°] = +17.8°

Fischer projections Fischer projections

COCO22HH

CHCH33

OHOH

OHOH

HH

HH

when carbon chain is vertical, same (or when carbon chain is vertical, same (or analogous) substituents on analogous) substituents on same sidesame side of of Fischer projectionFischer projection

COCO22HH

CHCH33

OHOH

OHOH

HH

HH

––9.5°9.5° +9.5°+9.5°

COCO22HH

CHCH33

HH

HH

HOHO

HOHO

Erythro(Erythro( 赤式赤式 ))

when carbon chain is vertical, same (or when carbon chain is vertical, same (or analogous) substituents on analogous) substituents on opposite sidesopposite sides of of Fischer projectionFischer projection

+17.8°+17.8° ––17.8°17.8°

OHOH

COCO22HH

CHCH33

HH

HH

HOHO

COCO22HH

CHCH33

OHOHHH

HHHOHO

Threo(Threo( 苏式苏式 ))

SS SSRR RR

2.3 环上含手性碳的化合物Two stereogenic centers in a ringTwo stereogenic centers in a ring

nonsuperposable mirror images; enantiomersnonsuperposable mirror images; enantiomers

transtrans-1-Bromo-1-chlorocyclopropane-1-Bromo-1-chlorocyclopropane

SS RRSS RR

Two stereogenic centers in a ringTwo stereogenic centers in a ring

nonsuperposable mirror images; enantiomersnonsuperposable mirror images; enantiomers

ciscis-1-Bromo-1-chlorocyclopropane-1-Bromo-1-chlorocyclopropane

SS SSSS RR

Two stereogenic centers in a ringTwo stereogenic centers in a ring

stereoisomers that are notstereoisomers that are notenantiomers; diastereomersenantiomers; diastereomers

ciscis-1-Bromo-1-chloro--1-Bromo-1-chloro-cyclopropanecyclopropane

transtrans-1-Bromo-1-chloro--1-Bromo-1-chloro-cyclopropanecyclopropane

SS RR RRRR

chiralchiralmesomeso

There are three stereoisomers of 1,2-dichloro-There are three stereoisomers of 1,2-dichloro-cyclopropane; the achiral (meso) cis isomer cyclopropane; the achiral (meso) cis isomer and two enantiomers of the trans isomer.and two enantiomers of the trans isomer.

Cyclic compoundsCyclic compounds

RRRR

chiralchiral

SS SS

2.4 Achiral Molecules withAchiral Molecules withTwo Stereogenic CentersTwo Stereogenic Centers

(( 有有 22 个手性中心的非手性分子个手性中心的非手性分子 ))

It is possible for a molecule to have It is possible for a molecule to have stereogenic centers yet be achiral.stereogenic centers yet be achiral.

2,3-Butanediol2,3-Butanediol

Consider a molecule with two equivalentlConsider a molecule with two equivalently substituted stereogenic centers such as y substituted stereogenic centers such as 2,3-butanediol.2,3-butanediol.

CHCH33CHCHCHCHCHCH33

HOHO OHOH

3322

Three stereoisomers of 2,3-butanediolThree stereoisomers of 2,3-butanediol

22RR,3,3RR 22SS,3,3SS 22RR,3,3SS

chiralchiral chiralchiral achiralachiral

CHCH33

CHCH33

OHOHHH

HHHOHOHH OHOH

CHCH33

CHCH33

HHHOHO HH

CHCH33

CHCH33

OHOH

OHOHHH


22RR,3,3RR 22SS,3,3SS

chiralchiral chiralchiral

these two arethese two areenantiomersenantiomers

22RR,3,3SS

achiralachiral

meso formmeso form


22RR,3,3RR 22SS,3,3SS

chiralchiral chiralchiral

CHCH33

CHCH33

OHOHHH

HHHOHOHH OHOH

CHCH33

CHCH33

HHHOHO

these two arethese two areenantiomersenantiomers

22RR,3,3SS

achiralachiral

HH

CHCH33

CHCH33

OHOH

OHOHHH

ExampleExample

4 stereogenic cente4 stereogenic centersrs

16 stereoisomers16 stereoisomers

OO

HOCHHOCH22CH—CH—CH—CHCHCH—CH—CH—CHCH

OHOH OHOH OHOH OHOH

HOHO OHOH

HH

HH

HOHO

HH33CC

HH

HHCHCH22CHCH22COCO22HH

CHCH33

HH

CHCH33

11 stereogenic centers11 stereogenic centers221111 = 2048 stereoisomers = 2048 stereoisomersone is "natural" cholic acidone is "natural" cholic acida second is the enantiomer a second is the enantiomer of natural cholic acidof natural cholic acid2046 are diastereomers of c2046 are diastereomers of cholic acidholic acid

Cholic acidCholic acid

maximum number of stereoisomers = 2n

where n = number of structural units capable of stereochemical variation

structural units include stereogenic centers and cis and/or trans double bonds

number is reduced to less than 2n if meso forms are possible

•How many stereoisomers?

3- 戊烯 -2- 醇

HOHO HH

EE RR

HH OHOH

EE SS

HHHOHO

ZZ RR

HH OHOH

SS

How many stereoisomers?How many stereoisomers? ZZ

第三节不含手性碳原子化合物的对映异构体一、丙二烯型化合物

CC CCH3

HH

CH3

C CCH3C

H H

CH3

2 、 3 - 戊二烯的对映异构体

手性轴CC Ca

bb

a

二、单键旋转受阻的化合物 COOH

NO2 HOOC

O2N

手性轴

三、把手化合物（ Ansa – compounds ）

OO

HOOC

£¨ CH2£©8

O O

COOH

£¨ CH2£©8

£¨ CH2£©10

OO

Br

Br£¨ CH2£©10

O O

Br

Br

四、含其他手性原子的化合物

NR1 R2

R3

NR2 R3

R4

R1

PR1 R2

R3

O

SR1 R2

R3

胺季胺盐五价磷化合物锍盐

第四节光活性物质的性质与旋光性的测定

1. 旋光异构体的物性比较2. 旋光性的测定

表 2- 甲基 -1- 丁醇对映体物理性质比较

化合物沸点（℃）密度折射率

（ 20 ℃ ）

比旋光度 []

(+)-2 甲基 -1- 丁醇 128 0.8193 1.4102 +5.756

(-)-2- 甲基 -1- 丁醇 128 0.8193 1.4102 -5.756

一般条件下，对映体性质完全相同

差别： 1 、对平面偏振光的旋转方向不同 2 、在手性环境中的反应速度不同

Properties of EnantiomersSame Bp, Mp, densitySame refractive indexDifferent direction of rotation in polari

meterDifferent interaction with other chiral

molecules Enzymes Taste buds(味蕾 ), scent(香气 )

表酒石酸的物理性质

酒石酸熔点 /℃比旋光度[]D25水溶液

溶解度 /（ g/100g水）

密度 g/ml ， 20 ℃ pKa1

pKa

2

左旋体 170 +12° 139 1.760 2.93 4.23

右旋体 170 -12 ° 139 1.760 2.93 4.23

内消旋体 140 不旋光 125 1.667 3.11 4.80

外消旋体 206 不旋光 20.6 1.680 2.96 4.24

History

1848 1848 巴黎师范大学巴黎师范大学 Lewis PasteurLewis Pasteur化学成绩中等化学成绩中等BesansonBesanson 皇家学院皇家学院重复结晶学实验重复结晶学实验282800CC以下结晶，酒石酸钠按以下结晶，酒石酸钠按

Polarized lightPolarized light

ordinary ordinary (nonpolarized) (nonpolarized) light consists of light consists of many beams many beams vibrating in vibrating in different planesdifferent planes

plane-polarized plane-polarized light consists of light consists of only those beams only those beams that vibrate in the that vibrate in the same planesame plane

Nicol prismNicol prism

Polarization of lightPolarization of light

Rotation of plane-polarized lightRotation of plane-polarized light

Optical Activity

Rotation of plane-polarized lightEnantiomers rotate light in opposite directions, but same number of degrees.

PolarimetryUse monochromatic light, usually sodium DMovable polarizing filter to measure angleClockwise = dextrorotatory = d or (+)Counterclockwise = levorotatory = l or (-)Not related to (R) and (S)

产生旋光的原因

两种圆偏振光

比旋光度 (Specific Rotation)

[ ]t =

L(dm) ×C(g/ml)

t ：温度：光源波长 L ：样品管长度 C ：样品浓度：旋光度右旋酒石酸的比旋光度为： [ ]D = +3.79 °(乙醇， 5% ）

旋光性的测定

左旋和右旋 ( - ) and ( + ) ( laevorotatory and dextrorotatory )

比旋光度 ( specific rotation) [α]tD= α/ ( c ╳ l)钠光 D:5893A影响α的因素：溶剂；温度； C ； l ；；［α］；外消旋体 ---- 一对对映异构体的等量混合物

Racemic mixture, racemate

有旋光性的化合物一定能测出旋光度吗？

1965 制出两个纯品无旋光度0.0000010

（ CH2 ） 3CH3CH3 （ CH2

） 5

CH2CH3

CH2CH2CH3

第五节反应中的立体化学与手性化合物制备

反应中的立体化学加成反应亲核取代消除反应

手性化合物制备

Biological Discrimination

Biological Significance of Chirality

Biological Significance of Chirality

Many reactions convert achiral Many reactions convert achiral reactants to chiral products.reactants to chiral products.

It is important to recognize, however, that if all of the components of the starting state (reactants, catalysts, solvents, etc.) are achiral, any chiral product will be formed as a racemic mixture.

more simply stated as "Optically inactive starting materials can't give optically active products."

Remember: In order for a substance to be optically active, it must be chiral and one enantiomer must be present in greater amounts than the other.

一、加成反应中的立体化学

立体专一反应（ stereospecific reaction ）

Br

CH3

HH

Br

CH3

Br2

a b

Br

CH3

HBr

HCH3

CH3

CH3

Br

H

H

Br

CH3

CH3

H

Br

Br

H

H

CH3

CH3

H

Br2

s

s

R

R

Example

CH3CH CH2

CH3COOH

O

H3C

O

CH2C

H

Chiral, but racemicAchiral

epoxidation from this direct

ion gives R epoxide

epoxidation from this direct

ion gives S epoxide

RR

SS

50%50%

50%50%

ExampleExample

CHCH33CHCH CHCH22

Chiral, but racemic(Chiral, but racemic(外消旋体外消旋体 ))

BrBr22, H, H22OO

CHCH33CHCHCHCH22BrBr

OHOH

AchiralAchiral

CHCH33CHCH CHCHCHCH33HBrHBr

CHCH33CHCHCHCH22CHCH33

BrBr

加成反应中立体化学规律

(1) 顺式加成 :B2H6;H2/Pd;冷稀的 KMnO4; 顺式烯烃—内消旋化合物反式烯烃 ---外消旋混合物

(2) 反式加成 : Br2;HOX;HX;H2SO4

顺式烯烃—外消旋混合物反式烯烃 --- 内消旋化合物

Qs ＆ As

KMnO4

1 OsO4

2 NaHSO3£¬H2O

cold,diluted

OH

OH

OH

OH

OH

OH

OH

OH

nucleophile attacks carbonnucleophile attacks carbonfrom side opposite bondfrom side opposite bondto the leaving groupto the leaving group

three-dimensionalthree-dimensionalarrangement of bonds inarrangement of bonds inproduct is opposite to product is opposite to that of reactantthat of reactant

SN2

SN2 ：构形反转SN1 ：外消旋化（构型反转／构型保持）

二、亲核取代中的立体化学二、亲核取代中的立体化学

CC

HH

CHCH33

BrBr

CHCH33(CH(CH22))55

CC

HH

CHCH33

HOHO

(CH(CH22))55CHCH33

NaOHNaOH

((SS)-(+)-2-Bromooctane)-(+)-2-Bromooctane ((RR)-(–)-2-Octanol)-(–)-2-Octanol

Stereospecific Reaction

++

rearrangementsare possible.

Ionization step gives carbocation; thre

e bonds to stereogenic center become

coplanarLeaving group shields one face of

carbocation; nucleophile attacks f

aster at opposite face.

More than 50%More than 50% Less than 50%Less than 50%

RR-(–)-2-Bromooctane-(–)-2-Bromooctane

HH

CC

CHCH33

BrBr

CHCH33(CH(CH22))55

((RR)-(–)-2-Octanol (17%))-(–)-2-Octanol (17%)

HH

CC

CHCH33

OHOH

CHCH33(CH(CH22))55

CC

HH CHCH33

HOHO

(CH(CH22))55CHCH33

((SS)-(+)-2-Octanol (83%))-(+)-2-Octanol (83%)

H2O

Stereochemistry of an SN1 Reaction

三、消除反应之立体化学E2 ：反式共平面消除(1) 反式共平面消除活化能最小(2)C -C 逐渐形成 P轨道最大重叠有利

C C

X

YB:

第六节外消旋体的拆分第六节外消旋体的拆分拆分（ Resolution ）：外消旋体分离成旋光体的过程提供手性环境和条件，使对映异构体表现出不同性质而得以拆分一、化学分离法与光活胺成盐、或与光活醇成酯使之转化为物理性质不同的非对映异构体

非外消旋体

外消旋体

（ + ） A （ - ） A

( + ) A

( - ) A+ ( + ) B

( + ) A ( + ) B

( - ) A ( + ) B

·ÖÀë( + ) A ( + ) B ( - ) A ( + ) B+

Resolution of EnantiomersReact a racemic mixture with a chiral compound

to form diastereomers, which can be separated.

二、生物分离法

CH2CHCOOH

NHCOCH3

( + ) - ±½±û°±Ëá ( - ) - N -ÒÒõ£±½±û°±Ëá

ÒÒõ£Ë®½âÃ¸

( + )

三、晶种结晶法

四、其他方法

手性色谱法，动力学拆分法，生成分子化合物法等。

Chromatographic Resolution of EnantiomersChromatographic Resolution of Enantiomers

本章小结本章小结

旋光异构现象旋光异构现象旋光异构现象旋光异构现象分子中没有对称因素→手征性分子→产生立体异构现象→异构体能使偏振光的振动平面发生旋转→旋光异构现象

手征性和手征性和旋光异构旋光异构手征性和手征性和旋光异构旋光异构

手征性分子旋光活性含 C* 的分子手征性分子

旋光异构体旋光异构体表示方法和命名表示方法和命名

旋光异构体旋光异构体表示方法和命名表示方法和命名

表示方法表示方法透视式和投影式命名（标记）命名（标记）相对构型—— D/L 命名法绝对构型—— RR/SS 命名法

各论各论各论各论含一个 C* 的化合物含两个不相同 C* 的化合物含两个相同 C* 的化合物环状化合物

旋光异构体性质旋光异构体性质旋光异构体性质旋光异构体性质对映异构体手性条件下性质不同，非手性条件下性质相同。非对映异构体物理性质不同，化学性质基本相同，但在同一反应中，反应速率不同。

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