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Alcohols Nomenclature of alcohols: IUPAC system نذكر اسم alkaneو نحذف منه حرف e و نستبدله ب ol و في حالة الترقيم نعد من الطرف الذي يعطى مجموعة OH أقل ترقيم و في حالة الترقيم نعد من الطرف الذي يعطى مجموعة OH أقل ترقيم
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في حالة alkene or alkyne نحذف حرف e و نستبدله ب ol في حالة alkene or alkyne نحذف حرف e و نستبدله ب ol و في حالة الترقيم نعد من الطرف الذي يعطى مجموعة OH أقل ترقيم و في حالة الترقيم نعد من الطرف الذي يعطى مجموعة OH أقل ترقيم Examples
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Common names Common names نذكر اسم alkylالمتصلة ب OH ثم نكتب كلمة alcohol نذكر اسم alkylالمتصلة ب OH ثم نكتب كلمة alcohol Examples
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Carbinol method Carbinol method تعتمد هذه الطريقة على أن CH3OH يسمى ب Carbinol و تسمى alcohols كمشتقات منه بذكر أسماء alkyl المستبدلة بدلا من ذرات الهيدروجين في مجموعة CH3 ثم نكتب كلمة Carbinol تعتمد هذه الطريقة على أن CH3OH يسمى ب Carbinol و تسمى alcohols كمشتقات منه بذكر أسماء alkyl المستبدلة بدلا من ذرات الهيدروجين في مجموعة CH3 ثم نكتب كلمة Carbinol Examples Examples
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IUPAC name 2-propen-1-ol2-Butanol2-Methyl-1-Propanol Common name Allyl alcohol Sec-Butyl alc. Isobutyl alc. Carbinol method Vinyl carbinol Ethyl methyl carbinol Isopropyl carbinol Examples of nomenclature
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Classification of alcohols According to number of OH groups Monohydroxy alcohols: which contain one OH group e.g. ethanolMonohydroxy alcohols: which contain one OH group e.g. ethanol Dihydroxy alcohols: which contain two OH group e.g. ethyleneglycol.Dihydroxy alcohols: which contain two OH group e.g. ethyleneglycol. Polyhydroxy alcohols: which contain more than two OH groups e.g. glycerol and carbohydrate.Polyhydroxy alcohols: which contain more than two OH groups e.g. glycerol and carbohydrate.
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According to number of OH groups According to number of OH groups Monohydroxy alcohols are classified according to type of carbon bearing OH into three types: Monohydroxy alcohols are classified according to type of carbon bearing OH into three types: 1ry alcohols: in which OH attach with 1ry carbon e.g. RCH2OH1ry alcohols: in which OH attach with 1ry carbon e.g. RCH2OH 2nd alcohols: in which OH attach with 2nd carbon e.g. R2 CHOH2nd alcohols: in which OH attach with 2nd carbon e.g. R2 CHOH t-alcohols : in which OH attach with tertiary carbon e.g. R3COHt-alcohols : in which OH attach with tertiary carbon e.g. R3COH
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Preparation of alcohols a) Preparation of 1ry alcohol1. a) Preparation of 1ry alcohol1. 1- Hydrolysis of alkene 1- Hydrolysis of alkene 2. Hydrolysis of alkyl halide
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E.g. conversion of benzene to benzyl alcohol E.g. conversion of benzene to benzyl alcohol 3. Reduction of carbonyl compound Reduction of aldehyde gives 1ry alcohol, while of ketone gives 2nd alcohol
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NaBH4 reduce C=O and not reduce C=C NaBH4 reduce C=O and not reduce C=C e.g. e.g. CH3CH=CH-CHO + NaBH4 CH3CH=CH-CH2OH Crotonaldehyde 2-Butenol CH3CH=CH-CHO + NaBH4 CH3CH=CH-CH2OH Crotonaldehyde 2-Butenol 4. Reduction of acids and esters Acids and esters are reduced to 1ry alcohol by use of LiAlH 4 E.g. CH 3 COOH + LiAlH 4 CH 3 CH 2 OH CH3COOCH2CH3 + LiAlH4 2 CH3CH2OH Also Na/ROH can reduce esters to 1ry alcohol
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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:
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b) Preparation of secondary alcohols b) Preparation of secondary alcohols Secondary alcohols are prepared from Grignard reagent and aldehyde other than formaldehyde.
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c) Preparation of tertiary alcohols Tertiary alcohols are prepared from Grignard reagent and ketones.
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Grignard reagent is used to synthesis many organic compounds e.g. Grignard reagent is used to synthesis many organic compounds e.g. Reactions of alcohols 1)Replacement of OH by halogen 1)Replacement of OH by halogen a) By reaction with HX ROH + HX RX + H2O ROH + HX RX + H2O X= I, Br and Cl X= I, Br and Cl e.g. CH3CH2OH + HBr CH3CH2Br +HOH e.g. CH3CH2OH + HBr CH3CH2Br +HOH b) By reaction with phosphorus halide
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Dehydration of alcohols Dehydration of alcohols See alkene Formation of esters Formation of esters e.g. CH3CH2OH + CH3COOH CH3COOCH2CH3 + H2O Ethanol acetic acid Ethyl acetate Differentiation between different types of alcohols 1.By oxidation a)1ry alcohol oxidize to give aldehyde or acid
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Examples of oxidizing agent are K2Cr2O7/ H2SO4, KMnO4 and Cu/250oC b)2nd alcohol oxidize to give ketone c) Tertiary alcohols do not oxidize Iodoform test This reaction occurs with alcohols containing Also aldehydes or ketones containing CH 3 -CO can give iodoform
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Examples of iodoform equations Examples of iodoform equations
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Mechanism of iodoform Mechanism of iodoform (a) For alcohols (a) For alcohols
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(b) For aldehyde and ketones (b) For aldehyde and ketones Only one aldehyde can give iodoform, this aldehyde is acetaldehyde, the mechanism of aldehyde and ketones are step 2, and 3 in alcohol. Only one aldehyde can give iodoform, this aldehyde is acetaldehyde, the mechanism of aldehyde and ketones are step 2, and 3 in alcohol. E.g. acetone E.g. acetone
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Ethers Ethers Nomenclature of ethers Nomenclature of ethers IUPAC nomenclature IUPAC nomenclature تسمى RO ب Alkoxy و تتم التسمية باعتبار RO فرع في سلسلة الالكان تسمى RO ب Alkoxy و تتم التسمية باعتبار RO فرع في سلسلة الالكانE.g. CH3O- CH3CH2O- CH3CH2CH2CH2O- CH3O- CH3CH2O- CH3CH2CH2CH2O- Methoxy Ethoxy Butoxy Methoxy Ethoxy Butoxy Examples of ethers Examples of ethers CH3OCH2CH2CH3 CH3CH2OCH2CH3 1-Methoxypropane Ethoxyethane
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Comman Nomenclature Comman Nomenclature نذكر أسماء الألكيل المتصلة بذرة الأوكسجين ثم نكتب كلمة ether نذكر أسماء الألكيل المتصلة بذرة الأوكسجين ثم نكتب كلمة ether Examples Examples CH3CH2OCH2CH3 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)
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Preparation of ethers From alcohols From alcohols Wiliamson synthesis Wiliamson synthesis It is reaction between alkoside and alkyl halide It is reaction between alkoside and alkyl halide E.g. preparation of diethyl ether E.g. preparation of diethyl ether
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Question 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 Answer
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Observation: Observation: Alkyl halide must be primary or secondary because t-alkyl halide undergoes loss of HCl (elimination) so it gives alkene not ether e.g. Alkyl halide must be primary or secondary because t-alkyl halide undergoes loss of HCl (elimination) so it gives alkene not ether e.g.
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Reaction of ethers Reaction with acid halide Reaction with acid halide
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Cyclic ethers تسمى Cyclic ethers ب alkene oxide أو نحدد رقمي ذرتي الكربون المتصلتين بذرة الأوكسجين و يسميا ب epoxy و ينسبا ل alkane تسمى Cyclic ethers ب alkene oxide أو نحدد رقمي ذرتي الكربون المتصلتين بذرة الأوكسجين و يسميا ب epoxy و ينسبا ل alkane
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Preparation 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.
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Examples
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