Alcohols Nomenclature of alcohols: IUPAC system نذكر اسم alkaneو نحذف منه حرف e و...
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Transcript of Alcohols Nomenclature of alcohols: IUPAC system نذكر اسم alkaneو نحذف منه حرف e و...
AlcoholsAlcohols
Nomenclature of alcohols:Nomenclature of alcohols:IUPAC systemIUPAC system
اسم اسم نذكر حرف alkanealkane نذكر منه نحذف حرف و منه نحذف ب eeو نستبدله ب و نستبدله olol و
مجموعة يعطى الذي الطرف من نعد الترقيم حالة في مجموعة و يعطى الذي الطرف من نعد الترقيم حالة في وOHOH ترقيم ترقيم أقل أقل
حالة حالة في حرف alkene or alkynealkene or alkyneفي حرف نحذف نستبدله ee نحذف نستبدله و وololب ب
يعطى الذي الطرف من نعد الترقيم حالة في يعطى و الذي الطرف من نعد الترقيم حالة في وترقيم OHOHمجموعة مجموعة ترقيم أقل أقل
Examples
Common namesCommon names اسم اسم نذكر ب alkylalkylنذكر ب المتصلة كلمة OHOHالمتصلة نكتب كلمة ثم نكتب alcoholalcoholثم
Examples
Carbinol methodCarbinol method
أن على الطريقة هذه أن تعتمد على الطريقة هذه ب CH3OHCH3OHتعتمد ب يسمى يسمىCarbinolCarbinol تسمى تسمى و بذكر alcoholsalcohols و منه بذكر كمشتقات منه كمشتقات
في alkylalkylأسماء أسماء الهيدروجين ذرات من بدال في المستبدلة الهيدروجين ذرات من بدال المستبدلةكلمة CH3CH3مجموعة مجموعة نكتب كلمة ثم نكتب CarbinolCarbinolثم
ExamplesExamples
IUPAC nameIUPAC name 2-propen-1-ol2-propen-1-ol 2-Butanol 2-Butanol 2-Methyl-1-Propanol2-Methyl-1-Propanol
Common nameCommon name Allyl alcohol Allyl alcohol Sec-Butyl alc. Sec-Butyl alc. Isobutyl alc. Isobutyl alc.
Carbinol methodCarbinol method Vinyl carbinol Vinyl carbinol Ethyl methyl Ethyl methyl carbinolcarbinol
Isopropyl carbinol Isopropyl carbinol
Examples of nomenclature
Classification of alcoholsClassification of alcohols
According to number of OH groupsAccording to number of OH groups• MonohydroxyMonohydroxy alcohols: which contain one OH group e.g. alcohols: which contain one OH group e.g.
ethanolethanol• DihydroxyDihydroxy alcohols: which contain two OH group e.g. alcohols: which contain two OH group e.g.
ethyleneglycol.ethyleneglycol.• PolyhydroxyPolyhydroxy alcohols: which contain more than two OH alcohols: which contain more than two OH
groups e.g. glycerol and carbohydrate.groups e.g. glycerol and carbohydrate.
According to number of OH groupsAccording to number of OH groups Monohydroxy alcohols are classified according to type of Monohydroxy alcohols are classified according to type of
carbon bearing OH into three types:carbon bearing OH into three types:
• 1ry alcohols: in which OH attach with 1ry carbon e.g. 1ry alcohols: in which OH attach with 1ry carbon e.g. RCH2OHRCH2OH
• 2nd alcohols: in which OH attach with 2nd carbon e.g. R2 2nd alcohols: in which OH attach with 2nd carbon e.g. R2 CHOHCHOH
• t-alcohols : in which OH attach with tertiary carbon e.g. t-alcohols : in which OH attach with tertiary carbon e.g. R3COHR3COH
Preparation of alcoholsPreparation of alcohols a) Preparation of 1ry alcohol1. a) Preparation of 1ry alcohol1. 1- Hydrolysis of alkene1- Hydrolysis of alkene
2 .Hydrolysis of alkyl halide
E.g. conversion of benzene to benzyl alcoholE.g. conversion of benzene to benzyl alcohol
3 .Reduction of carbonyl compound
Reduction of aldehyde gives 1ry alcohol, while of ketone gives 2nd alcohol
NaBH4 reduce C=O and not reduce C=CNaBH4 reduce C=O and not reduce C=C
e.g. e.g. CH3CH=CH-CHO + NaBH4 CH3CH=CH-CH2 OH CH3CH=CH-CHO + NaBH4 CH3CH=CH-CH2 OH
Crotonaldehyde 2-Butenol Crotonaldehyde 2-Butenol
4 .Reduction of acids and esters
Acids and esters are reduced to 1ry alcohol by use of LiAlH4
E.g. CH3COOH + LiAlH4 CH3CH2OH
CH3COOCH2CH3 + LiAlH4 2 CH3CH2OH
Also Na/ROH can reduce esters to 1ry alcohol
Grignard reagent is used to prepare 1ry, 2nd, and t-alcohols
a) Preparation of 1ry alcohol
1ry alcohol is prepared from Grignard reagent and formaldehyde
Grignard reagent can be prepared as follow:
bb) ) Preparation of secondary alcoholsPreparation of secondary alcohols
Secondary alcohols are prepared from Grignard reagent and aldehyde other than formaldehyde.
cc) ) Preparation of tertiary alcoholsPreparation of tertiary alcohols
Tertiary alcohols are prepared from Grignard reagent and ketones.
Grignard reagent is used to synthesis many organic Grignard reagent is used to synthesis many organic compounds ecompounds e..gg..
Reactions of alcoholsReactions of alcohols
1)Replacement of OH by halogen1)Replacement of OH by halogen
a) By reaction with HXa) By reaction with HX
ROH + HX RX + H2OROH + HX RX + H2O
X= I, Br and ClX= I, Br and Cl
e.g. CH3CH2OH + HBr CH3CH2Br +HOHe.g. CH3CH2OH + HBr CH3CH2Br +HOH
b) By reaction with phosphorus halide
R OHPCl5
R Cl + HCl + POCl3
R OHSOCl2
R Cl + HCl + SO2
R OHPCl3
3 R Cl3 + H3PO3
Dehydration of alcoholsDehydration of alcoholsSee alkeneSee alkene
Formation of estersFormation of esterse.g. CH3CH2OH + CH3COOH CH3COOCH2CH3 + H2Oe.g. CH3CH2OH + CH3COOH CH3COOCH2CH3 + H2O
Ethanol acetic acid Ethyl acetate
Differentiation between different types of alcohols1. By oxidation
a)a) 1ry alcohol oxidize to give aldehyde or acid1ry alcohol oxidize to give aldehyde or acid
RCH2OH[O]
RCHOaldehyde
[O]RCOOH
acide.g.
CH3CH2CH2OH
propan-1-ol
[O]CH3CH2CHO
propionaldehyde
[O]CH3CH2COOH
propionic acid
Examples of oxidizing agent are K2Cr2O7/ Examples of oxidizing agent are K2Cr2O7/ H2SO4, KMnO4 and H2SO4, KMnO4 and Cu/250oCCu/250oC
b)2nd alcohol oxidize to give ketoneb)2nd alcohol oxidize to give ketone
c) Tertiary alcohols do not oxidizec) Tertiary alcohols do not oxidize
Iodoform test
This reaction occurs with alcohols containing
Also aldehydes or ketones containing CH3-CO can give iodoform
Examples of iodoform equationsExamples of iodoform equations
Mechanism of iodoformMechanism of iodoform
(a) For alcohols(a) For alcohols
(b) For aldehyde and ketones(b) For aldehyde and ketones
Only one aldehyde can give iodoform, this aldehyde is Only one aldehyde can give iodoform, this aldehyde is acetaldehyde, the mechanism of aldehyde and ketones are acetaldehyde, the mechanism of aldehyde and ketones are step 2, and 3 in alcohol.step 2, and 3 in alcohol.
E.g. acetoneE.g. acetone
EthersEthers
Nomenclature of ethersNomenclature of ethers
IUPAC nomenclatureIUPAC nomenclature
تسمى تسمىRORO ب بAlkoxyAlkoxy باعتبار التسمية تتم باعتبار و التسمية تتم فرع فرع RORO وااللكان سلسلة االلكان في سلسلة في
E.g. E.g. CH3O-CH3O- CH3CH2O-CH3CH2O- CH3CH2CH2CH2O- CH3CH2CH2CH2O- MethoxyMethoxy Ethoxy ButoxyEthoxy Butoxy
Examples of ethersExamples of ethers CH3OCH2CH2CH3 CH3CH2OCH2CH3
1-Methoxypropane Ethoxyethane
Comman NomenclatureComman Nomenclature أسماء أسماء نذكر كلمة ألألللاانذكر نكتب ثم األوكسجين بذرة المتصلة كلمة كيل نكتب ثم األوكسجين بذرة المتصلة كيل
etherether
Examples Examples
CH3CH2OCH2CH3 C6H5OCH3 (CH3) 3 C-OCH2CH3CH3CH2OCH2CH3 C6H5OCH3 (CH3) 3 C-OCH2CH3
Diethyl ether methyl phenyl ether t-Butyl ethyl Diethyl ether methyl phenyl ether t-Butyl ethyl
ether (Anisole)ether (Anisole)
Preparation of ethersPreparation of ethers From alcoholsFrom alcohols
Wiliamson synthesisWiliamson synthesis
It is reaction between alkoside and alkyl halideIt is reaction between alkoside and alkyl halide
E.g. preparation of diethyl etherE.g. preparation of diethyl ether
QuestionQuestion Show how could you prepare the following ethers:Show how could you prepare the following ethers:
(a) Anisole (phenyl methyl ether) (b) t- butyl ethyl et (a) Anisole (phenyl methyl ether) (b) t- butyl ethyl et
AnswerAnswer
Observation:Observation: Alkyl halide must be primary or secondary because t-alkyl halide Alkyl halide must be primary or secondary because t-alkyl halide
undergoes loss of HCl (elimination) so it gives alkene not ether e.g.undergoes loss of HCl (elimination) so it gives alkene not ether e.g.
Reaction of ethersReaction of ethers
Reaction with acid halideReaction with acid halide
Cyclic ethersCyclic ethers
تسمى تسمىCyclic ethersCyclic ethers ب بalkene oxidealkene oxide ذرتي رقمي نحدد ذرتي أو رقمي نحدد أوب يسميا و األوكسجين بذرة المتصلتين ب الكربون يسميا و األوكسجين بذرة المتصلتين و و epoxyepoxyالكربون
ل ل ينسبا alkanealkaneينسبا
Preparation of cyclic ethersPreparation of cyclic ethers
In case of unsymmetrical cyclic ethers, the product depends on the reaction condition
In case of acidic medium, nucleophile goes to more steric carbon i.e. carbon containing less number of hydrogen.
In case of basic medium, nucleophile goes to less steric carbon i.e. carbon containing great number of hydrogen.
Examples