Organic Compounds with Functional Groups Containing Oxygen - I

1
(No Transcript)
2
Session
Organic Compounds with Functional Groups
Containing Oxygen - I
3
Session Objectives

1. Preparation of alcohols
2. Intermolecular dehydration
3. Esterfication
4. Iodoform reaction
5. Identification of different alcohols

4
Preparation of alcohols

• Reduction of carbonyl compounds
• Hydration of Alkenes
• Grignard reactions

5
Reduction of Carbonyl Compounds
Reduction of aldehydes and ketones
Strong reducing reagent are required.
Reduction of carbohylic acids and their
derivatives
6
Reagents used in reduction
Reduce all the compounds except unsaturation
Can not reduce Acids, estersacid anhydride and
unsaturation
Can reduce any groups and also unsaturation
Can reduce other groups except acid chloride
7
Hydration of Alkenes

• Acid catalyzed Hydration
• Oxymercuration-Demercuration
• Hydroboration-Oxidation

8
Acid-Catalyzed Hydration of Alkenes

• Markovnikov addition
• Formation of most stable carbocation
• Shifts/rearrangements possible

9
Hydration of Alkenes via Oxymercuration/Demercurat
ion

• Markovnikov addition
• Typically no shifts/rearrangements
• Mercurinium ion involvement

10
Hydroboration - Oxidation of Alkenes

• Anti-Markovnikov addition
• No shifts/rearrangements
• Syn addition

11
Grignard Addition Reactions

• Addition to Aldehydes/Ketones
• Addition to Esters
• Addition to Epoxides

12
Grignard Additions to Aldehydes/Ketones
Formation of primary, secondary, and tertiary
alcohols
13
Grignard Additions to Esters
Formation of secondary and tertiary alcohols
14
Grignard Addition to Epoxides
15
Typical Alcohol Reactions

• Salt formation
• Dehydration to alkene
• Oxidation to aldehyde, ketone
• Substitution to form alkyl halide
• Reduction to alkane
• Esterification
• Williamson synthesis of ether

16
Reaction with Active Metals
17
Dehydration of Alcohols
18
Oxidation of Alcohols
19
Alcohol Conversion to Alkyl Halides

• Reaction with Hydrogen halides
• Reaction with Thionyl chloride
• Reaction with Phosphorus trihalides or
  pentahalides

20
Hydrogen halide conversion of alcohols to alkyl
halides
21
Alcohols to Alkyl Chlorides via Thionyl Chloride
22
Alcohols to Alkyl Halides via Phosphorus Halides
23
Ester Formation from Alcohols
24
Haloform Reaction
Methyl carbinol cleavage to give Carboxylic acids
and Haloform
25
Physical properties
Alcohols consist of two parts, an alkyl group and
a hydroxyl group. Due to which they have
following properties
High boiling points
They are capable to form hydrogen bonds.
26
Distinction between 1, 2 and 3 alcohols
VictorMeyer test
1 alcohols
blood red colouration
2 alcohols
blue colouration
3 alcohols does not react.
27
Lucas test
Lucas reagent
conc.hydrochloric acid and anhydrous zinc
chloride.
28
Lucas test
Immediate reaction
29
Illustrative example
Cyclobutyl bromide on reaction with Mg / dry
ether forms an organometallic (A) The
organometallic reacts with ethanol to give an
alcohol (B) With an equivalent amount of HBr
gives 1bromo1methyl cyclopentane (C) Write the
structures of (A),(B) and (C) and explain how
(C) is obtained from (B).
Solution
30
Solution
Ring transformation
20 cation
30 cation
31
(No Transcript)