SYNTHESIS OF

ALKANE AND

CYCLOALKANE

Introduction

Enhancingconclusion

Empowering

alkane

Cycloalkane

General fact

Fill in the blank

True of false

crossword

MatchHydrogenation

Gridnard reagent

Reduction by zinc

END

Reduction by LiAlH

4

and NaBH4

Code translator

intro

I wonder what is alkane actually…

anyone can explain it to me?

I wonder what is alkane actually…

anyone can explain it to me?I heard about

cycloalkane…but I don’t know what is

that..

I heard about cycloalkane…but I don’t know what is

that..

How can we synthesis both of them?

How can we synthesis both of them?

Can you give us the answers?

Can you give us the answers?

BACK

Cn

H2n

+2

Alkane

Number of C atoms Molecular formula Name (n-alkane)1 CH4 Methane

2 C2H6 Ethane

3 C3H8 Propane

4 C4H10 Butane

5 C5H12 Pentane

6 C6H14 Hexane

Alkanes are hydrocarbons in which all the carbon-carbon bonds are

single bond

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Cn

H2n

Cycloalkane

Number of C atoms Molecular formula Name (n-alkane) Shape

3 C3H6 Cyclopropane

4 C4H8 Cyclobutane

5 C5H10 Cyclopentane

6 C6H12 Cyclohexane

Cycloalkanes are the alkanes in which all or some of

carbon atoms are arranged in a ring

BACK

composed of tetrahedral,

sp3 hybridized C atoms

two types of alkanes: acyclic

alkanes (CnH2n+2),

cycloalkanes(Cn

H2n)

have only nonpolar C-C

and C-H bonds

no functional group and

undergo few reactions

named with the suffix -ane

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HYDROGENATION OF ALKENES AND ALKYNES

hydrogenation of

alkenes and

alkynes

react with H2 in the present of metal

catalysts (Pd, Ni and Pt) and in solvent

EtOH

1 mole H2 for alkenes2 moles H2

for alkynes

C C + H2 C C

C C + H2 C C + H2 C C

C C + H2 C C

C C + H2 C C + H2 C C

Pd,Pt,NiPd,Pt,Ni

EtOHEtOH

EtOHEtOH EtOHEtOH

Pd,Pt,NiPd,Pt,Ni Pd,Pt,NiPd,Pt,Ni

CH3 CH3 CH3 H CH3

CH3C CH C CH3 + 2 CH3C C C CH3

CH3 H H CH3

Pd/Ni/Pt

EtOH

Acyclic Alkane

+ H2Pd/Ni/Pt

EtOH

Cyclic Alkane

HYDROGENATION OF ALKYNES

H C C H + H2

C C + H2 C CH

H

H

HH

H

H

H

H

H

Pd/Pt/Ni

EtOH

Pd/Pt/Ni

EtOH

1)

2)

3)

CH3

+ H2Pd/Pt/Ni

EtOH

CH2 CH CH CH3

CH3

+ H2

Pd/Pt/Ni

EtOH

CH3 CH CH CH3CH3CH2CH2CH3

1)

2)

3)

CH3

+ H2Pd/Pt/Ni

EtOH

CH3

CH2 CH CH CH3

CH3

+ H2

Pd/Pt/Ni

EtOH CH3 CH CH CH3

CH3

CH3 CH CH CH3CH3CH2CH2CH3+ H2

Pd/Pt/Ni

EtOH

BACK

X is a halogen atom, usually chlorine,

bromine, or iodine.

R is an alkyl or aryl

(based on a benzene

ring) group

Grignard reagents are

organomettalic compounds in which the

metal is mostly

magnesium.the general molecular formula is

RMgX

Whose discover that?

Whose discover that?

It is discoverer by French chemist Victor Grignard, who was a

co recipient of the 1912 Nobel Prize for Chemistry for this

work

It is discoverer by French chemist Victor Grignard, who was a

co recipient of the 1912 Nobel Prize for Chemistry for this

work

Grignard reagents will

react with compounds containing

acidic hydrogen

atoms

Hydrogen atoms

attached to electronegative atoms (e.g. S, N,

O)

Reaction of Grignard reagent

with water to produce

alkane

H3C-Mg-Br H-O H

H3C-H Mg2+

OH Br+ + + +-

Yes, I got alkane.Yes, I got alkane.

CH3CH2MgBr + H20 CH3CH3 + Mg(OH)Br

MgBr

+ H2O + Mg(OH)Br

CH3CH2CH2MgBr + H20 CH3CH2CH2 + Mg(OH)Br CH3 CH3

CH3

MgBr

+ H2O

CH3

+ Mg(OH)Br

What is the structure of R?

H O

R

+RMgBr

R = ????

Answer :

BACK

Reduction

Aqueous acid

Zinc, Zn

R-X R-HZn/CH3COOH

Br

CH3 CH2 CH CH3

H

CH3 CH2 C CH3

H

Br

H

Zn/CH3COOH

Acyclic Alkane

Zn/CH3COOH

Cyclic Alkane

1)

2)

3)

CH3CH2CH2CH2Cl

Zn/CH3COOH

CH2Br

Zn/CH3COOH

CH3CH2CH2CH CH2CH3

CH2CH2F

CH3CH2CH2CH CH2CH3

CH2CH3

1)

2)

3)

CH3CH2CH2CH2Cl

Zn/CH3COOH CH3CH2CH2CH3

CH2Br

Zn/CH3COOH

CH3

CH3CH2CH2CH CH2CH3

CH2CH2F

CH3CH2CH2CH CH2CH3

CH2CH3

Zn/CH3COOH

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Reduction by lithium halide (LiAlH4) and sodium tetrahydridoborate

(NaBH4)

Reduction by lithium halide (LiAlH4) and sodium tetrahydridoborate

(NaBH4)

LiAlH4 and NaBH4 function as

nucleophiles

LiAlH4 and NaBH4 function as

nucleophiles

Electrophiles accept

electrons to form the

bond

Electrophiles accept

electrons to form the

bondPrimary and

secondary alkyl halides are

reduced with NaBH4 while 1o, 2o

and 3o alkyl halides are

reduced with LiAlH4

Primary and secondary alkyl

halides are reduced with

NaBH4 while 1o, 2o and 3o alkyl halides are

reduced with LiAlH4

H B

H

H

HNa Cl CH2 CH2 CH3

polarized bond

+-CH2 CH2 CH3H NaCl

BH3

+

+

Alkane produce

EXAMPLE

LiAlH4LiAlH4

CH3CH2CH2CH2Cl

CH3

CH3CH2CH2CH3

CH3

Br

NaBH4NaBH4

CH3CH2CH2CH2Cl

CH2CH2I

CH2CH2Br

CH3CH2CHCH2CH2CH3

CH2CH2Br

LiAlH4

LiAlH4

NaBH4

NaBH4

Can you answer

it?

Ermmm…I will try.

CH3CH2CH2CH2Cl

CH2CH2I

CH2CH2Br

CH3CH2CHCH2CH2CH3

CH2CH2Br

LiAlH4

LiAlH4

NaBH4

NaBH4

DID YOU GET THE ANSWER?

CH3CH2CH2CH3

CH2CH3

CH2CH3

CH3CH2CHCH2CH2CH3

CH2CH3

Well, I’m done it.Well, I’m done it.

BACK

Corey-Posner, Whiteside-House Synthesis

Lithium dialkyl cuprate (R2CuLi)Lithium dialkyl

cuprate (R2CuLi)Alkyl halide

(R’-X)Alkyl halide

(R’-X)

New alkane

(R-R’)

New alkane

(R-R’)

Organocopper compound

(R-Cu)

Organocopper compound

(R-Cu)

An organic compound that involves the

reaction of a lithium dialkyl cuprate with an alkyl halide to form a

new alkane, an organocopper

compound and a lithium halide

Lithium halide

(Li-X)

Lithium halide

(Li-X)

R2CuLi + R’-X R-R’ + R-Cu + Li-X

EXAMPLE

(CH3CH3)2CuLi + CH3CH2CH2CH2CH2Cl

CH3CH2CH2CH2CH2CH2CH3 + CH3CH3Cu + LiCl

Et2O

CH2CH2Br + (CH3) 2CuLi

CH2CH2 CH3 + CH3Cu + LiBr

Et2O

EXERCISE

CH3CH2CH2CH2CH2I + (CH3)2CuLi

CI + ( )2CuLi

+ (CH3CH2)2CuLi

CH3

Et2O

Et2O

Et2O

TRY UR BEST

TRY UR BEST

CH3CH2CH2CH2CH2I + (CH3)2CuLi

CI + ( )2CuLi

+ (CH3CH2)2CuLi

CH3

Et2O

Et2O

Et2O

ANSWER

CH3CH2CH2CH2CH2 CH3

+ CH3Cu + LiI

+ Cu + LiCl

+ CH3CH2Cu + LiBr

CH3

CH3CH2

CH3

BACK

Match the following item

Alkanes

Cycloalkanes

sp3 hybridized C atoms

Hydrogenation

Reduction

Metal catalyst + EtOH

Alkanes

CnH2n

Zinc + aqueous acid

CnH2n+2

Let’s check the answers

Alkanes

Cycloalkanes

sp3 hybridized C atoms

Hydrogenation

Reduction

Metal catalyst + EtOH

Alkanes

CnH2n

Zinc + aqueous acid

CnH2n+2

BACK

M S A F E S D F 4 K H Y O P A

Q E W A T N E V L O S S A K Q

A G T T Y G R O P K I A E L U

E U E A A S E D Y W P I N H E

R I 5 A L W R T G A O D A T O

F J G I I C Q E S T K L K G U

H B H L O T A O P E L H L F S

J J V J U K E T W R T U A C A

L M K N R O R A A E I Y G B C

T H R E E R T S H L T O P N I

T K U 1 0 7 3 R D C Y R I U D

H E R C F V B M N L K S E N 2

E R T F Y U G V D 2 9 P T N H

A A L K Y L H A L I D E O K P

E R T F U I H T E W Q A L J K

Tips: the arrows can be…

M S A F E S D F 4 K H Y O P A

Q E W A T N E V L O S S A K Q

A G T T Y G R O P K I A E L U

E U E A A S E D Y W P I N H E

R I 5 A L W R T G A O D A T O

F J G I I C Q E S T K L K G U

H B H L O T A O P E L H L F S

J J V J U K E T W R T U A C A

L M K N R O R A A E I Y G B C

T H R E E R T S H L T O P N I

T K U 1 0 7 3 R D C Y R I U D

H E R C F V B M N L K S E N 2

E R T F Y U G V D 2 9 P T N H

A A L K Y L H A L I D E O K P

E R T F U I H T E W Q A L J K

BACK

1) The important components in hydrogenation of alkene and alkynes are …… and …… (EtOH).

2) Reduction of alkyl halide can be carried out through …… processes which are Grignard reagent hydrolysis, reduction by zinc in the presence of aqueous acid and reduction by lithium aluminium hydride.

3) Grignard reagent hydrolysis needs …… to be carried out.4) Reduction by zinc must be in the presented of ……5) The product of alkyl halide after undergoes reduction by

lithium aluminium hydride is……6) Corey-Posner, Whiteside-House synthesis is an organic

reaction of a lithium dialkyl cuprate with a/an …… to form a new alkane, an organocopper compound and a lithium halide.

1) The important components in hydrogenation of alkene and alkynes are metal catalyst and solvent (EtOH).

2) Reduction of alkyl halide can be carried out through three processes which are Grignard reagent hydrolysis, reduction by zinc in the presence of aqueous acid and reduction by lithium aluminium hydride.

3) Grignard reagent hydrolysis needs water to be carried out.4) Reduction by zinc must be in the presented of aqueous

acid.5) The product of alkyl halide after undergoes reduction by

lithium aluminium hydride is alkane.6) Corey-Posner, Whiteside-House synthesis is an organic

reaction of a lithium dialkyl cuprate with an alkyl halide to form a new alkane, an organocopper compound and a lithium halide.

BE THE BEST AMONG THE BEST

BE THE BEST AMONG THE BEST

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What’s he saying?Use the secret code translator below to find out!

ANSWER : REDUCTION OF ALKYL HALIDES IS ONE OF THE SYNTESIS OF ALKANES

I V W F X G R L M LU Z O P B O S Z O R W V H - - - - - - - - - - - - - - - - - - - - - - -

R H L M V L U G S V H B M G V H R H L U - - - - - - - - - - - - - - - - - - - -

Z O P Z M V H- - - - - - -

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1. 1o, 2o and 3o alkyl halides are reduced with NaBH4TRUE FALSE

2. LiAlH4 and NaBH4 function as nucleophiles TRUE FALSE

3. We also can produce alkane through reduction of zinc

TRUE FALSE

4. Primary and secondary alkyl halides are reduced with LiAlH4

TRUE FALSE

5. C9H19CH2BR + LiAlH C9H19CH3TRUE FALSE

You can do it!

You can do it!

Don’t give upDon’t give up

Answer: 1) False 2) true 3) true 4) false 5) true

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SYNTHESIS

ALKANES

+ CYCLOALK

ANES

SYNTHESIS

ALKANES

+ CYCLOALK

ANESHydrogenation of alkenes ( ) and alkynes

( )

Hydrogenation of alkenes ( ) and alkynes

( )

Corey-Posner, Whiteside-House

Synthesis

Corey-Posner, Whiteside-House

Synthesis

Reduction of Alkyl HalidesReduction of Alkyl Halides

Grignard reagent hydrolysis

R-Mg-X + H-OH R-H + Mg(OH)X

Reduction by lithium aluminium hydride

R-X R-H

Reduction by zinc in the presence of aqueous

acid

R-H R-H

LiAlH4

Zn/CH3COOH

CONCLUSION

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