Fy organic Chemistry semester I Unit I

Fy organic Chemistry semester I Unit I

Alkanes  

 Functional Group : Single covalent bond 

Definition : The aliphatic, unsaturated, hydrocarbons containing carbon - carbon single bond is called alkanes.

General formula : CnH2n +2      {n = 1,2,3,.....}

i) Common name system : 

The common names of former four alkanes are derived from their sources such as methane, ethane, propane and butane.

The common names of remaining alkanes are derived on the basis of number of carbon atoms representing in greek numericals followed by the suffix 'ane' as below.

Alkane with five carbon atoms called pentane.

C5H12              Pent+ane     = pentane

C6H14               Hex+ane      = Hexane 

C7H16         Hept+ane     = Heptane

C8H18         Oct+ane       = Octane 

C9H20            Non+ane      = Nonane 

C10H22           Dec+ane       = Decane 

Further more use the prefixes n, Iso & Neo when ever neccessary.

ii) IUPAC system : 

IUPAC means International Union of Pure & Applied Chemistry.

In this system with common names of first four members of alkanes are selected as it is such as methane, ethane, propane & butane.

Do not use the prefixes n, Iso & Neo in IUPAC system.

Following are the IUPAC rules used as determine the IUPAC names of alkanes.

Rule 1 : Select the longest carbon chain.

Count the number of carbon atoms in normal chain only.

Find the name of parent alkane.

Rule 2 : Give the numbering to normal carbon atom from that terminal carbon atom nearest to branched carbon atom (alkyl group).

Rule 3 : Give name and position (location) of branched groups (alkyl groups).

Rule 4 : It alkane contains 2,3,4 similar alkyl groups, use the prefixes di, tri & tetra respectively.

Rule 5 : If alkane contains dissimilar branched alkyl groups, suggest their names by alphabetical order. 

 Sr. No

 Formula

 Common name 

 IUPAC name

 1

 CH4

 Methane 

 methane 

 2

 CH3-CH3

 Ethane 

 ethane 

 3

 CH3-CH2-CH3

 Propane

 propane

 4

 CH3-CH2-CH2-CH3

 n Butane

 butane

 5

 

 Iso Butane 

 2− methylpropane

 6

 CH3-CH2-CH2-CH2-CH3

 n Pentane

 pentane

 7

 

 Iso Pentane 

 2− methylbutane

 8

 

 Neo Pentane

 2,2− dimethylpropane

Alkenes 

Fun. group formula  →  C = C

Name of fun. group →  carbon - carbon double bond or olefinic double bond. 

Definition : The aliphatic, unsaturated, hydrocarbons containing Carbon = Carbon double bond is called alkenes.

General Formula : CnH2n [ n = 2,3,4,....]

Nomenclature : 

Common name system : 

The common names of Alkenes are derived as using following steps.

1. Count the total number of carbon atoms in alkene molecule, Find the name of parent alkane.

2. Replace 'ane' suffix of an alkane with suffix 'ene' hence it becomes Alkylene.

3. Use the prefixes n, Iso & Neo whenever needed.

4. Now the position of double bond by using α, β, γ letters to normal carbon chain. These letters can be given from that terminal carbon nearest to C = C bond.

 IUPAC system : 

Following are the Rules can be employed to find the IUPAC names of alkanes.

Rule 1 : 

Select the longest carbon chain containing C = C bond functional, find the name of parent alkane.

Replace ending 'ane' suffix to alkane with suffix 'ene'. This it becomes alkene.

Rule 2 :

Give numbering from that terminal carbon atom nearest to C = C bond.

Rule 3 :

Give name & position of branched group.

Give the location of C = C functional group.

Rule 4 : 

If alkene contains 2,3,4 similar branched groups use the prefixes di, tri & tetra respectively.

Rule 5 : 

If alkene contains different branched groups, suggest their names by alphabetical order.


 Sr. No

 Formula 

 Common name 

 IUPAC name 

 1

 CH2 = CH2

 Ethylene

 ethene

 2

 CH3-CH = CH2

 Propylene

 propene

 3

 CH3-CH2-CH = CH2

 n,α -Buty-lene

 1-butene or but-1-ene

 4

 CH3 - CH = CH - CH3

 n,β-Buty-lene

 2-butene or but-2-ene

 5

 

 Iso α- Butylene

 2-methyl-1-propene

         OR
2-methylprop-1-ene

 6

 

 Neo-Pentylene

 2,2-dimethylbut-1-ene


Alkynes [Acetylenes]

Fun. group formula  → C ≡ C

Fun. Group name → carbon - carbon triple bond OR Acetylenic triple bond.

Definition : The aliphatic, unsaturated, hydrocarbons containing ( C ≡ C ) carbon carbon triple bond is called alkynes.

General Formula : CnH2n-2

Nomenclature : There are three system of nomenclature.

1. Common name system : 

The common names of alkynes are derived from their sources. These common names are limited given below.

1)  CH ≡ CH                 → Acetylene     

2)  CH3 - C ≡ CH         → Allylene

3)  CH3 - CH2- C ≡ CH → n,α-Crotonylene

4) CH3 - C ≡ C - CH3     → n,β-Crotonylene

2. Derived System 

I) According to this system first member of CH ≡ CH  called Acetylene.

II) The remaining member are considered the alkyl derivatives of Acetylenes & called alkyl acetylenes.

III) Use the prefix 'di' when two alkyl groups are similar & attached to acetylene part of group.

IV) When two alkyl groups different attached to Acetylene part given their names by alphabetical order.

V) Use the prefixes n, Iso, Neo, sec & tert for alkyl groups. Whenever necessary.

3. IUPAC system 

Following rules are used to determine the IUPAC names of Acetylenes.

Rule No. 1: 

Select the longest carbon chain containing C ≡ C group count the number of carbon atoms in normal chain only.

Find the name of parent alkane.

Replace ending 'ane' suffix with 'yne' suffix. Hence it becomes alkune.

Rule No. 2:

Start numbering from that terminal carbon atom nearest to C ≡ C group.

Rule No. 3:

Give the name & position of branched group.

Give the position of  C ≡ C group.

Rule No. 4:

If alkyne contains 2,3,4 similar branched groups, use the prefixes di, tri & tetra respectively.

Rule No. 5: 

If alkyne contains dissimilar branched groups. Give their names by alphabetical order.


 Sr. No

 Formula

 Common name 

 IUPAC name 

 1

 chloromethane

 Methylchloride

 chloromethane

 2

 bromoethane

 Ethylbromide

 bromoethane

 3

 1-iodopropane

 n-Propyliodide

 1-iodopropane

 4

 1-bromobutane

 n-Butylbromide

 1-bromobutane

 5

 1-chloro-2-methylpropane

 Isobutylchloride

 1-chloro-2-methylpropane

 6

 2-bromobutane

 Sec.butylbromide

 2-bromobutane

 7

 2-chloro-2-methylpropane

 tert.butylchloride

 2-chloro-2-methylpropane

 8

 1-iodp-2,2-dimethylpropane

 Neopentyliodide

      OR
Neoamyliodide

 1-iodp-2,2-dimethylpropane


Halo Arenes 

Fun. group formula →   - X

Fun. group name →   halide OR halo

Definition :

The aromatic compounds obtained by replacing one or more hydrogen atoms of aromatic hydrogen (Benzene) with equal number of halogen atoms called halo arenes.

Nomenclature of Mono halo arenes :

1. Common name system :

I) The mono halo arenes are called Aryl halides.

II) The mono halogen derivatives of benzene called phenyl halides.

III) Use the prefixes ortho (o), meta (m) & para (p) whenever needed.

2. IUPAC name system :

I) Convert halogen as halo.

II) Give the name of parent aromatic hydrogen carbon.

III) Thus it becomes halo arenes (haloarenes).

IV) Give numbering from principle functional group. (-X) 


 Sr. No 

 Formula

 Common name 

 IUPAC name 

 1

 

 PhenylChloride

 chlorobenzene

 2

 

 PhenylBromode

 bromobenzene

 3

 

 PhenylIodide

 iodobenzene

 4

 

 o-chlorotoluene

 2-cholotoluene

        OR
1−chloro−2−methylbenzene

 5

 

 p-chlorotoluene

 4-chlorotoluene

        OR
1-choloro-4-methylbenzene

 Alcohols:


Fun. group formula →  -OH

Name of functional group  →  hydroxyl

Alcohols: 

The aliphatic, hydroxyl compounds which are obtained from Aliphatic hydrocarbons by replacing one or more hydrogen atoms of aliphatic hydrocarbons [ alkanes, alkenes, alkynes] with equal number of hydroxyl (-OH) group called alcohols.

Alkyl alcohols :

The monohydric alcohols obtained from alkanes by replacing one hydrogen atom with one hydroxyl group with general formula R-OH CnH2n+ 1 OH called alkyl alcohols.

Nomenclature of Alkyl Alcohols [alkanols]

1. Common name system :

I) The monohydric alcohols of alkanes are called alkyl alcohols.

II) Use the prefixes n, Iso & neo whenever necessary.

III) Use the prefixes sec. & tert. when -OH group bonded to secondary & tertiary carbon atoms respectively.

2. IUPAC system :

Rule No. 1:

Select the longest carbon chain with -OH group.

Count the number of carbon atoms in normal chain only.

Find the name of parent alkane.

Replace ending 'e' of an alkane with 'ol' suffix. Thus it becomes 'alkanol'.

Rule No. 2:

Give the numbering to carbon atoms from that terminal carbon atoms nearest to -OH group.

Rule No. 3: 

Give name & position of branched group.

Give the position of -OH group.

Rule No. 4:

If alcohol contains 2,3,4 similar branched use the prefixes di. tri & tetra respectively.

Rule No. 5: 

The alcohol contains dissimilar branched group suggest their names by alphabetical order.

 Sr. No 

 Formula

 Common name 

 IUPAC name

 1

 

 Methyalcohol 

 methanol

 2

 

 Ethyalcohol

 ethanol

 3

 

 n-Propylalcohol

 n-propanol

         OR
propan-1-ol

 4

 

 IsoPropylalcohol

        OR
Sec.Propylalcohol

 2-propanol 

         OR
propan-2-ol

 5

 

 n-Butylalcohol

 1-butanol

      OR
butan-2-ol

 6

 

 IsoButylalcohol

 2−methylptopsn−1−ol

 7

 

 Sec.Butylalcohol

 butan-2-ol

 8

 

 tert.Butylalcohol

 2-methylpropan-2-ol

 9

 

 Vinylalcohol

 ethenol

Phenols 

Fun. group formula   -OH 

Name of gun. group  phenolic hydroxyl group 

Definition :

The aromatic hydroxyl compounds containing one or more -OH group directly attached to carbon atom of benzene ring called phenols.

Phenol or carbolic acid

The aromatic hydroxy compound having one hydroxyl group directly attached to carbon atom of benzene ring called phenol or carbolic acid.

Nomenclature :

1. Common name system of phenol :

I) The phenol is called phenol or carbolic acid by this system.

II) Select the prefixes ortho (o), para (p) & meta (m) for its derivatives.

2. IUPAC system :

I) The IUPAC name of carbolic acid is hydroxy benzene phenols or benzenol.

II) Give the position of substituents by numbers.

 Sr. No 

 Formula

 Common name 

 IUPAC name 

 1

 phenolbenzenol,phenol

 Phenol

   OR
Carbolic acid

 phenolbenzenol 

          OR
hydroxybenzene

 2

 2-chlorophenol,

 o-chlorophenol

 2-chlorophenol

 3

 4-chlorophenol

 p-cholorophenol

 4-chlorophenol

Carboxylic acid

Fun. group formula  →  - COOH

Name of fun. group →  carboxyl group 

General formula →  CnH2n+1 (n = 1,2,3,...)

Definition :

The derivatives of alkanes obtained by replacing one hydrogen atom of alkanes with one carboxyl group with general formula R- COOH or CnH2n+1  COOH (n = 1,2,3,...) called mono carboxylic acid.

Nomenclature :

1) Common name system :

I) The common names of carboxylic acids are derived from their sources.

II) Use the prefixes m, Iso & neo whenever needed.

IUPAC system :

Rule No. 1:

Select the longest carbon chain containing  - COOH group.

Count the number of carbon atoms in normal chain along with carbon atom of  - COOH group .

Find the name of parent alkane.

Replace ending 'e' of alkane with 'oic acid' term, Thus it becomes alkanoic acid.

Rule No. 2:

Start numbering to normal chain carbon atom from carbon atom of  - COOH group.

Rule No. 3: 

Give the name and position of branched groups.

Rule No. 4:

It acid contains 2,3&4 similar branched groups, use the prefixes di, tri & tetra respectively.

Rule No. 5:

It acid contains dissimilar branched groups suggest their names by alphabetical oders.


 Sr. No

 Formula 

 Common name 

 IUPAC name 

 1

 

 Formic acid

[Formica = Redant]

 methanoic acid

 2

 

 Acetic acid 

[Acetum = vinegar]

 ethanoic acid

 3

 

 Propionic acid

[Propiona = first fat]

 Propanoic acid

 4

 

 n-Butyric acid

[Butyrum  = Butter]

 butanoic acid

 5

 

 IsoButyric acid

[above source]

 2-methylpropanoic acid

 6

 

 n-valeric acid

[Valerian tree]

 pentanoic acid

 7

 

 Isovaleric acid

[above source]

 3−methylbutanoic acid

 8

 

neovaleric acid 

 2,2−dimethylpropanoic acid

 9

 

 n-caproic acid

[caprum = Intestine of  goat]

hexanoic acid 

Acid Anhydrides

Fun. group formula 



Name of fun. group : acid anhydride

Definition :

The derivatives of carboxylic acids obtained on condensation reaction of two monocarboxylic acids with elimation of water molecule called acid anhydrides.

Nomenclature :

1. Common name system :

I) Find the common name of carboxylic acid and replace acid term with anhydride.

The resultant name is common name.

2.IUPAC system :

I) Find the IUPAC name of carboxylic acid [alkanoic acid].

II) Replace acid term with anhydride it becomes alkanoic anhydride.

 Sr. No 

 Formula 

 Common name 

 IUPAC name 

 1

 

 Acetic anhydride

 ethanoic anhydride

 2

 

 Propionic anhydride

 propanoic anhydride

 3

 

 n-Butyric anhydride

 butanoic anhydride

 4

 

 Benzric anhydride

 benzoic anhydride

Acid Chloride


Fun. group formula :


 

Name of Fun. group : acid chloride


Defi : 

    The derivatives of mono carboxylic acid obtained by replacing -OH of -COOH group with -Cl having genetal formula R-CO-Cl called Acid chlorides.


Nomenclature : 

1) Common name system : 

I) Find the common name of acid based on number of carbon atoms.

II) Replace 'ic acid' term with 'yl chloride' term.


2) IUPAC name system :

I) Find the IUPAC name of acid [ alkanoic acid ]

II) Replace 'ic acid' term with 'yl acid' term, hence it becomes alkanoyl chloride.

 Sr. No 

 Formula 

 Common name 

 IUPAC name 

 1

 

 Formyl chloride

 methanayl chloride

 2

 

 Acetyl chloride

  ethanoyl chloride

 3

 

 Propionyl chloride

 propanoyl chloride

 4

 

 n-Butyryl chloride

 butanoyl chloride

 5

 

 Benzoyl chloride

 benzoyl chloride

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