BBR 26703 ana,ena,keton.pdf

7/24/2019 BBR 26703 ana,ena,keton.pdf

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Bab 2:MENULIS STRUKTUR KIMIA ORGANIK

Hatijah BasriUniv.Tun Hussein Onn Malaysia


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Objektif

Mengenalpasti jeniskumpulan berfungsi sebatian

Melukis struktur kimiasebatian organik mengikut

kumpulan berfungsi


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Overview Struktur Kimia Organik

Kumpulan-kumpulan berfungsi dalam kimia organik:

Alkana (alkane) dan Alkil halida (alkyl halide)

Alkena (alkene) dan Alkuna (alkyne)

Alkohol dan eter

Sebatian karbonil

-Aldehid dan keton

- Asid Karboksilik dan ester


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Sebatian organik (Sebatian karbon)

Definisi:Kimia Organik ialah kajian kimia sebatianyang mengandungi karbondan hidrogen.

Apakah keistimewaan karbon? Hampir 90 % bahanyang digunakan/berada oleh/dalam badan kitamengandungi karbon.

Aplikasi kimia organik

Perubatan Industri Petroleum

Industri Tekstil

Metaboolisme Manusia Plastik dan polimer

Petrokimia Sains Genetik.


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*Sebatian Organik kegunaan dalamaplikasi perubatan

Sulfonamide-asas bagibeberapa drugs, agenantimikrob sintetik

anthracyclines, banyak digunakansebagai penawar kanser sejak 1960s

Xopenex

(levalbuterolHCl)InhalationSolution

Antihypercholesterolemiccompounds lovastatinand simvastatin arewidely used in medicinefor the lowering of levelsof blood cholesterol

steroid - moleculesthat are critical forkeeping the bodyrunning smoothly
http://localhost/var/www/apps/conversion/tmp/scratch_1//patentimages.storage.googleapis.com/WO2002072566A1/imgf000003_0001.png


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Beberapa produk kimia organik

DNA

Minyak pati

Ubatan

Bahan Aktif Farmaseutikal

Materials

Petrol

Pigmen


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Ciri utama Sebatian Organik

Mudah terbakar dan mudah terurai kepada gas(jika tidak mengandungi gabungan logamdalam struktur).

Amnya, tbls kimia bagi sebat organik adalahperlahan.

Sebahagian sebatian organik mungkinmengandungi komponen halogen (less

flammable)

yang tinggi e.g. (X = F, Cl, Br, I,).

**How many H atom can bind to C atom?


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Kumpulan Berfungsi

Kumpulan Berfungsi:atom atau kumpulanatom dalam molekul yang menunjukkan setciri fizikal dan/atau kimia tertentu

Kumpulan berfungsi penting untuk 3 sebab;1. unit-unit ini membahagi sebatian-sebatian

organik kepada kelas-kelas.

2. Unit ini merupakan tapak bagi bermulanya tblaskimia.

3. Asas bagi penamaan sebatian organik.


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Penamaan (Nomenclature): RingkasanKump Berfungsi Bermula .. Berakhir.. Bilangan C

Alkana Met ana 1

Alkena Et ena 2

Alkuna Prop una 3

Alkohol But ol 4

Aldehid Pent .al 5

Keton Heks on 6

Asid Karboksilik Hept asidoik 7

Ester Oct R. oat 8Alkil Halida Non il halida 9

Eter Dec R.. R.. eter 10

Aromatik


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Beberapa contoh:

Lukis dan namakan hidrokarbon berikut :(a) alkohol, 5 atom C

(b) keton, 3 atom C

(c) Asid Karboksilik, 7 atom C

Beri nama sebatian mengikut IUPAC :(a) CH3CH2COH

(b) CH3CH2COCH3(c) CH2=C(CH3)CH3(d) CH3CH2COOCH3(e)


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Alkana, CnH2n+2


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Isomerism

In chemistry, isomers are compounds with thesame molecular formulabut different structural

formulas.[1]Isomers do not necessarily share

similar properties, unless they also have the

same functional groups. There are manydifferent classes of isomers, like stereoisomers,

enantiomers, geometrical isomers, etc. (see

chart below). There are two main forms of

isomerism: structural isomerismand

stereoisomerism

N l & K i
http://en.wikipedia.org/wiki/Chemistryhttp://en.wikipedia.org/wiki/Molecular_formulahttp://en.wikipedia.org/wiki/Structural_formulahttp://en.wikipedia.org/wiki/Structural_formulahttp://en.wikipedia.org/wiki/Isomer#cite_note-1http://en.wikipedia.org/wiki/Functional_grouphttp://en.wikipedia.org/wiki/Structural_isomerismhttp://en.wikipedia.org/wiki/Stereoisomerismhttp://en.wikipedia.org/wiki/Stereoisomerismhttp://en.wikipedia.org/wiki/Structural_isomerismhttp://en.wikipedia.org/wiki/Functional_grouphttp://en.wikipedia.org/wiki/Isomer#cite_note-1http://en.wikipedia.org/wiki/Structural_formulahttp://en.wikipedia.org/wiki/Structural_formulahttp://en.wikipedia.org/wiki/Molecular_formulahttp://en.wikipedia.org/wiki/Chemistry


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Nomenclature & Keisomeran

Alkanes

ButanaISOMERS

2-metil propana

Pentana

ISOMERS2-metil butana

2,2-dimetil propana

Heksana

ISOMERS

Heptana

ISOMERS


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Nomenclature (Penamaan) & Keisomeran

Isomer Struktur:

Sebatian dengan sifat fizikal dan kimia berbeza tetapi formulamolekul yang sama.

Stereoisomer

Sebatian2 dengan formula molekul sama tetapi susunanatom yang berbeza.Berbeza antara satu sama lain pada orientasi kumpulandalam molekul.Stereoisomer teringkas ialah isomer cisdan trans.Butena, C4H8, wujud dalam isomer cisdan trans.


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Namakan 2 sebatian ini dannyatakan jika keduanya adalahisomer antara satu sama lain.

Bagaimana dengan menamakan

sebatian alkana siklik?

siklopentana

siklobutana


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cis-3,4-dimetil-3-heptena

C=C

CH3

H3C

CH3CH2CH2CH2CH3

trans-1,2-dikloro-1-butena

C=C

HCl

CH3CH

2

Cl


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Alkena, CnH2n


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Ciri utama molekul alkena ialah ikatan dubel.

Ik terdiri drp 1 ik. kovalen (sigma) dan 1 ik. (pi).

Sebat mengandungi ik. Dubel dikatakan tidak tepu

(unsaturated)kerana boleh bertbls dengan hidrogendengan kehadiran mangkin.

Sebatian yang dihasilkan ialah sebatian tepu

(saturated) / tidak mengandungi ik. berbilang (multiple).

Sifat fizik: hampir sama dengan alkana i.e. wujud

sebagai gas pada suhu bilik.Isomer alkena mempunyai takat didih hampir sama

(sukar dipisah).

Ciri Alkena:


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Alkene Nomenclature

The rules for alkenes are similar to those used for alkanes. The following rules

summarize alkene nomenclature.

1. Identify the longest continuous chain of carbon atoms that contains the carbon-

carbon double bond.

2. The parent name of the alkene comes from the IUPAC name for the alkane with

the same number of carbon atoms, except the -aneending is changed to -enetosignify the presence of a double bond. For example, if the longest continuous chain

of carbon atoms containing a double bond has five carbon atoms, the compound is a

pentene.

3. Number the carbon atoms of the longest continuous chain, starting at the endclosest to the double bond. Thus, is numbered from right to left, placing the double

bond between the second and third carbon atoms of the chain. (Numbering the

chain from left to right incorrectly places the double bond between the third and

fourth carbons of the chain.)


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The position of the double bond is indicated by placing the

lower of the pair of numbers assigned to the double-bonded

carbon atoms in front of the name of the alkene. Thus, the

compound shown in rule 2 is 2-pentene.

The location and name of any substituent molecule or groupis indicated. For example, is 5-chloro-2-hexene.

Finally, if the correct three-dimensional relationship is

known about the groups attached to the double-bondedcarbons, the cisor transconformation label may be assigned.

Thus, the complete name of the compound in rule 4 (shown

differently here)

Alkene Nomenclature

cis-5-chloro-2-hexene


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Alkene Reactions

Oxidation

Electrophilic Addition rxn

Halogenation

Hydrohalogenation

Hydration (Direct water addition)

Hydrogenation


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Alkene Reactions

Oxidation

(purple) (brown)

*Baeyer Test

Cleavage reaction (further oxidation)

* any water-soluble compound that produces this color change when added

to cold potassium permanganate must possess double or triple bonds.


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**Markonikovs Rule: The halide component of HX bonds preferentially at the more

highly substituted carbon, whereas the hydrogen prefers the carbon which already

contains more hydrogens.

+

Hydrohalogenation/Alkyl halide addition


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Alkynes, CnH2n-2


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Physical Properties of Alkynes

The physical properties of alkynes are very similar to those of

the alkenes. Alkynes are generally nonpolar molecules with little solubility in

polar solvents, such as water.

Solubility in nonpolar solvents, such as ether and acetone, is

extensive.

Like the alkanes and alkenes, alkynes of four or fewer carbon

atoms tend to be gases.

Name: ?

Answer: 5-chloro-2-hexyne


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The principal reaction of the alkynes is addition across the

triple bond to form alkanes.These addition reactions are analogous to those of the

alkenes.

Hydrogenation

Alkyne Addition Reactions

Name the end product of 5-methyl-3-heptynes

after hydrogenation process

A: 3-methylheptane


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Halogenation

Hydrohalogenation

**Markonikovs Rule: The halide component of HX bonds preferentially at the more

highly substituted carbon, whereas the hydrogen prefers the carbon which already

contains more hydrogens.

Alkyne Addition Reactions


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Alkyne Reactions

Combustion?

C6 combustion?


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Preparation of Alkynes

Deydrohalogenation/Dihaloalkane elimination

Dehalogenation


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Mechanism dihaloalkane elimination


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Substitution

* acetylene

Acidity of alkynes


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From alkene



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Exercise:

Question 1: What are the major products of the

following reactions: a.) 1,2-Dibromopentane with sodium amide in liquid

ammonia

b.) 1-Pentene first with Br2and chloromethane,

followed by sodium ethoxide (Na+-O-CH2CH3)

Question 2: What would be good starting molecules

for the synthesis of the following molecules:


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Cont..

Question 3: Use a 6 carbon diene to synthesize a

6 carbon molecule with 2 terminal alkynes.


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Reactions Summary (Alkenes)

Type Reaction

Addition of Halogen, X2 >C=C< + X2 >CH(X)-CH(X)< (X= Cl, Br)

Addition of Polar reagents >C=C< + H-OH >CH(H)-CH(OH)C=C< + H-X >CH(H)-CH(X)< (X = Cl, Br, F, I)

Hydroboration-Oxidation RCH2=CH2 (BH3) (RCH2=CH2)3B (H2O2/OH-)

RCH2CH2OH

Addition of Hydrogen >C=C< + H2 (Pd, Pt or Ni) >CH(H)-CH(H)C=CH-CH=C< + X2 >CH(X)-CH(X)-C=CH +>CH(X)-CH=CH-C(X)C=CH-CH=C< + HX >CH-CH(X)-C=CH + >CH-

CH=CH-C(X) 50 mL)

Ethanol/ethyl alcohol/grain alcohol

The acohol of alcoholic beverages; the fermentation of honey, grain, or

fruit juices to yield beers and wines was probably the first chemicalreaction to be discovered; metabolized in the body to produce

acetaldehyde

Isopropyl alcohol/2-propanol

Rubbing alcohol is 70%isopropyl alcohol and 30% water


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Alcohols are classified as primary (1), secondary

(2), or tertiary (3) according to how many carbongroups are attached to the carbon bearing the OH

group:

R-CH2-OH primary (1)R-CH(R)-OH secondary (2)

R-C(R)(R)-OH tertiary (3)

The number of hydrogens on the carbon bearing the

OH group does affect some chemical properties.

Classification of Alcohols


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Some properties of alcohol

Polar solventdue to hydrogen bonding

Since the OH group makes alcohols polar, they will

mix with polar solvents like water as long as the

carbon chain is fairly short.*The longer the carbon chain,the less soluble the alcohol is.

Because alcohols hydrogen bond to each other,

theyhave higher boiling points than alkanes of the

same molecular weight. *The boiling point of alcohols

increases as the molecules become larger.e.g. bp: phenol (181.7 C); toluene (110.6 C)

S ti f th O


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Some properties of ether

Ethers are relatively stable and unreactive in many respect; some react slowly with

air to produceperoxides(contain O-O).The peroxides from low MW ethers such as diiso-propyl ether and tetrahydrofuran

are explosiveand extremely dangerous.

Ethers boiling point(bp) are somewhat higherthan bp of comparable alkane. E.g.

B.p.(C): CH3-O-CH3(-25) ; CH3CH2CH3(-45)

O

Acidic cleavage:

Claisen Rearrangement

Reaction of ether

O-CH2-CH=CH2Claisen rearrangement

250 C

OHCH2-CH=CH2

HBr,H2O

Reflux

O-CH2-CH3 OH

+ CH3CH2Br


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Reaction of Alcohols

Dehydration of Alcohols to Produce Alkenes

CH3CH2CH(OH)CH3 CH3CH=CHCH3+ H2O

(+CH3CH2CH=CH2)

Metal salt (Alkoxide) formation:Alcohols are only slightlyweaker acids than water, with a Kavalue of approximately

11016. The reaction of ethanol with sodium metal (a base)

produces sodium ethoxide and hydrogen gas. This reaction is

identical to the reaction of sodium metal with water.

H2SO4, 180 C



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Alkyl Halide formation

Dehydration of alcohols to produce ethers

R-OH + R-OH R OR + H2O

Oxidation of alcohols

*R-OH RH-C=O R-C=O-OH

*1 : Aldehyde; 2 : ketone


H2SO4, 140 C

KMnO4 KMnO4

R ti f Al h l


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Substitution, Lucas Reagent (ZnCl2)

CH3CH2OH + HCl CH3CH2Cl + H2O

alcohol + hydrogen halide alkyl halide + water (ZnCl2)

This reaction with the Lucas Reagent (ZnCl2) is a qualitative test

for the different types of alcohols because the rate of the reaction

differs greatly for a primary, secondary and tertiary alcohol.

The difference in rates is due to the solubility of the resulting

alkyl halides

Tertiary Alcohol turns cloudy immediately (the alkyl halide is not

soluble in water and precipitates out)

Secondary Alcohol turns cloudy after 5 minutes

Primary Alcohol takes much longer than 5 minutes to turn cloudy


Alcohols preparation


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Preparation from.. Reaction

Reduction of Carbonyl Compounds R-C=O ([H]) R-CH-OH; [H] = reducing

agent e.g. LiAlH4, NaBH4

*R-C=O-H R-CH-OH (1)

R-C=O-R R-CHR-OH (2)

Reduction of carboxylic Acids and Esters R-C=OOH or R-C=OOR R-CH-OH

(not as rapid as carbonyl compounds)

Reaction of carbonyl compounds with

Grignard Reagents

RC=O R-CH2OH + HOMgX

p p

1. LiAlH4, ether

2. H3O+

1. NaBH4,ethanol

2. H3O+

1. NaBH4,ethanol

2. H3O+

1. RMgX, ether

2. H3O+


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Aldehydes and Ketones-Carbonyl compounds

N l


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Nomenclature

Formula Common name/systematic name

HCHO Formaldehyde/Methanal

CH3CHO Acetaldehyde/Ethanal

CH3CH2CHO Propionaldehyde/Propanal

CH3CH2CH2CHO Butyraldehyde/Butanal

CH3CH2CH2CH2CHO Valeraldehyde/Pentanal

CH2=CHCHO Acrolein/Propenal

Benzaldehyde/BenzenecarbaldehydeCHO

N l t


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Nomenclature

Formula Common name/systematic name

CH3C=OCH3 Dimethyl ketone(acetone)/Propanon

CH3CH2C=OCH2CH3 Diethyl ketone/3-Pentanone

Benzophenone/Diphenyl ketone

C=O


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Aldehydes and Ketones

contain a carbonyl (C=O)

groupC HO

CH3 - C- H

O

CH3 -C-CH3

O

C

O

Functionalgroup

Acetaldehyde(an aldehyde)

Acetone(a ketone)

Functionalgroup

Reaction of Aldehyde and Ketones


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Oxidation: RCH=O RC=O-OH

Addition of Grignard reagents:

CrO3,H3O+

Acetone, 0 C

*Aldehydes are readily oxidized to yield carboxylic acids but ketones are

generally inert towards oxidation.

e.g. CH3(CH2)4CH=O CH3(CH2)4C=O-OH

CrO3,H3O+

Acetone, 0 C

RC=ORR-MgX, Ether

H3O+

RRRC-OH



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Reduction: RCR=O RCH-OH

Tollens Test

*In a Tollens test, Ag+

is reduced to Ag0

, leaving inside surface of the flaskcoated with a reflective silver mirror.

* Only aldehyde (ketone will not) response in Tollens test.

:H-

From NaBH4

CHOHCN

CN-C-OH

CHO HO-C=OAg2O

NH4OH, H2O, EtOH+ Ag


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Carboxycylic Acid and Esters-Carbonyl compounds

N l t


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Nomenclature

Formula Common name/systematic

nameHCOOH Formic acid/Methanoic acid

CH3COOH Acetic acid/Ethanoic acid

CH3CH2COOH Propanoic acid

CH3CH2CH2COOH Butanoic acid

CH3CH2CH2CH2COOH Pentanoic acid

CH2=CHCHO Acrolein/Propenal

Benzoic acidCOOH


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Carboxylic Acids

contain a carboxyl (-COOH) group

C O

O

H CH3

-C-O-H

O

CH3

COOH CH3

CO2

H

: ::

:

or or

Acetic acid

(a carboxylic acid)

Functionalgroup


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Carboxylic Esters

Ester:a derivative of a carboxylic acidin which the carboxyl hydrogen is

replaced by a carbon group

C O

O

Functionalgroup

CH3 -C-O-CH2 -CH3

Ethyl acetate

(an ester)

:

:

: :O


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Carboxylic Amide

Carboxylic amide, commonly referred to as anamide: a derivative of a carboxylic acid inwhich the -OH of the -COOH group is replacedby an amine

the six atoms of the amide functional group

lie in a plane with bond angles of

approximately 120

CH3 -C-N-H

H

Acetamide(a 1 amid e)

O

C N

O

Functionalgroup


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For most carboxylic acids, Kais approximately 10-5; e.g.

acetic acid, Ka= 1.76 10-5.

Although much weaker than mineral acids, carboxylic acid

are much stronger acids than alcohols

Acid carboxylic preparation

Oxidation of Primary Alcohol

CH3(CH2)8-OH CH3(CH2)8C(OH)=O

Oxidation of a substituted alkylbenzene with KMnO4orNa2Cr2O7; benzoic acid is formed

CrO3

H3O+

CH3 KMnO4

H2O,95 C

COOHNO2 NO2


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Amines

contain an amino group; an sp3-hybridized

nitrogen bonded to one, two, or three carbonatoms

an amine may by 1, 2, or 3

C H3 N H

H

C H3 N H

C H3

C H3 N C H3

C H3

Methylamine(a 1 amine)

Dimethylamine(a 2 amine)

Trimethylamine(a 3 amine)

: : :


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Summary

For each functional groups discussed (alkane alkenes


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For each functional groups discussed (alkane, alkenes,

alkynes, alcohol&ether, aldehyde&ketone, acid

carboxylic & ester); please look into their

Nomenclature, try the most difficult one, Also look into

naming some common aromatic, amine and amide

compounds.

Special reactions such oxidation/reduction; memorizereagents involved.

The most discussed method of preparation, the

reagents and expected outcome

Special test to differentiate certain carbonyl

compounds or between alkanes, alkenes and alkynes

BBR 26703 ana,ena,keton.pdf

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