Alcohols
Download as PPTX, PDF
1 like3,606 views
This document provides information about alcohols including their nomenclature, classification, properties, preparation methods, and important examples. Alcohols are defined as compounds with a hydroxyl group attached to a saturated carbon. They are named using IUPAC nomenclature by identifying the carbon chain and hydroxyl group position. Alcohols are classified as primary, secondary, or tertiary based on the carbons bonded to the hydroxyl carbon. Their properties include higher boiling points than alkanes and solubility in water. Common preparation methods include hydration of alkenes, addition to carbonyl groups, and reduction of carboxylic acids. Important alcohols include methanol, ethanol, glycerol
Alcohols
- 1. Organic Name : Functional Group Alcohol
- 2. Group 1 : Abdurrohman Dzaky Al Hafidz M. Andika Aryana Reky Hermawan Saptio Aji Suhartini Lestari Putri
- 4. Definition Alcohol are compounds in wich a hydroxyl group (-OH) is attached to a saturated carbon The general formula of alcohol is ROH (R= alkyl, substitution alkyl, or syclic hidrokarbon) Example: CH3-OH (metanol) CH3CH-OH (etanol) Alcohols
- 5. Nomenclature of Alcohols IUPAC System Step 1 : Name the longest chain to which the hydroxyl group is attached. (alkane e + ol = Alkanol) Step 2 : Number the longest chain to give the lowest number to the carbon attached to the hydroxyl group Step 3: Indicate the position of the hydroxyl group by the number of the carbon atom to which is attached Step 4: Indicate the position of other substitutients or multiple bonds by number Alcohols
- 6. Nomenclature of Alcohols IUPAC System Example: 3 2 1 CH3CH2CH2OH 1 2 1-propanol 3 CH3CH2CH2 2-propanol OH Alcohols
- 7. Classification of Alcohols Monohydric alcohols are classified as primary (1o), secondary (2o), or tertiary (3o) : In primary (1o) alcohols the OH is attached to a C atom which is attached to one other In secondary (2o) alcohols the OH is attached to a C atom which is attached to two other In tertiary (3o) alcohols the OH is attached to a C atom which is attached to three other Alcohols
- 8. Classification of Alcohols Example: primary (1o) : R-CH2-OH CH3-CH2-CH2-OH 1-propanol (n-propyl alcohol) secondary (2o): R-CH-OH R CH3-CH-OH 2-propanol (isopropyl alcohol) CH3 Alcohols
- 9. Classification of Alcohols Example: tertiary (3o) : R R-CH-OH R CH3 CH3-CH-OH 2-methyl-2-propanol (t-buthyl alcohol) CH3 Alcohols
- 10. Physical Properties of Alcohols Boiling Points Alcohol have hinger boiling points than alkanes of similar molecular weight. Alcohol boiling points increase as carbon-chain length increases. Example: CH3-OH methyl alcohol BM= 32 oC= 65 CH3-CH2-OH ethyl alcohol BM= 46 oC= 78 CH3-CH2-CH2-OH n-propyl alcohol BM= 60 oC= 97 Alcohols
- 11. Physical Properties of Alcohols Solubility The polar part of the alcohol molecule increases solubility in water, but the non polar part decrease solubility. Size of the non polar alkyl group is large the solubility of alcohol in water decrease dramatically Alcohols
- 12. Chemical Properties of Alcohols 1. Reaction with active metals Alkoxides are formed by Na, Mg, Al etc H3C-CH2-OH Na H3C-CH2-ONa Sodium ethoxide Alcohols
- 13. 2. Ester Formation O H3C-CH2-OH + H3C-CH2-C-OH ethanol propanoic acid O H3C-CH2-C-O-CH2-CH3 + H2O diethyl ester Alcohols
- 14. 3. Dehydration (Reaction with sulphuric acid) a. Alkene Formation OH Conc. H SO H3C-CH2-CH-CH3 2 4 H3C-CH2-CH=CH2 + H3C-CH=CH-CH3 2-butene Major Product Alcohols 1-butene Minor Product
- 15. 3. Dehydration (Reaction with sulphuric acid) b. Ether Formation 2 H3C-CH2-OH ethanol Conc. H2SO4 140o H3C-CH2-O-CH2-CH3 H O + 2 diethyl ether Alcohols
- 16. 3. Dehydration (Reaction with sulphuric acid) c. Alkyl hydrogen sulphates formation H3C-CH2-OH + HO-SO2OH ethanol H3C-CH2-O-SO2OH + H2O Ethyl hydrogen sulphate Alcohols room temperature
- 17. 4. Alkyl halides formation (R-X) a. Reaction with thionyl chloride (SOCl2) H3C-CH2-OH + SOCl2 ethanol H3C-CH2-Cl + SO2 + HCl Ethyl chloride Alcohols
- 18. 4. Alkyl halides formation (R-X) b. Reaction with phosphorus halides (PX3 or PX5) H3C-CH2-OH + PCl5 ethanol 3 H3C-CH2-OH + PCl3 ethanol H3C-CH2-Cl + POCl3 + HCl Ethyl chloride H3C-CH2-Cl + H3PO3 Ethyl chloride Alcohols
- 19. 5. Reaction with hydrogen halides (HX) HCl react with alcohols only in the presence of catalyst (anhydrous ZnCl2). No catalyst is required in the case of HBr or HI H3C-CH2-OH + HBr ethanol H3C-CH2-Br + H2O Ethyl bromide Alcohols
- 20. 6. Reaction withnitric acid (HNO3) alkyl nitrates are formed H3C-CH2-OH + HBr ethanol H3C-CH2-O-NO2 + H2O ethylnitrate 7. Oxydation Different types of alcohols give different products on oxidation. Most widely used oxidizing agents are KMnO4 + H2SO4 and Na2Cr2O7 + H2SO4 Alcohols
- 21. a) Primary alcohols are oxidized to aldehydes, which are, in turn, easily axidized to carboxilic acids. The reaction can be stoped at the aldehyde stage, by removing them from the oxidizing medium as they are farmed (e.g. Destilation) O H3C-CH2-OH + Ethylalcohol O H3C-C-H acetaldehyde H3C-C-OH aceticacid Alcohols
- 22. b.) secondary alcohol are oxidazed to ketones O O H3C-CH-CH3 + H3C-C-CH3 + H2O Isoprophyl alcohol acetone c.) Tertiary alcohol dont undergo oxidation under normal condition. OH H3C-C-CH3 + NO REACTION (NR) CH3 Tert-buthyl alcohol Alcohols
- 23. 8. Reaction with hot copper ( catalytic dehydrogenation) Different types of alcohols give different products when their vapours are passed over copper gauze at 3000C a) Primary alcohols give aldehydes + hydrogen O H3C-CH2-OH H3C-C-H + H2 Ethylalcohol Acetaldehyde Alcohols
- 24. b. ) Secondary alcohols give ketone + hydrogen OH O H3C-C-CH3 H3C-C-CH3 + H2 Isoprophyl alcohol Acetone c. ) Tertiary alcohols give alkenes + water OH CH2 H3C-C-CH3 H3C-C + H2O CH3 CH3 Tert-butyl alcohol 2-methyl propene Alcohols
- 26. 2. Hydration of Alkenes Alkenes react with conc. H2SO4 to form alkyl hydrogen sulphates which on hydrolysis yield alcohols Sesuai hukum Markovnikov maka bagian positifnya akan menuju ke bagian C yang Hnya paling banyak Alcohols
- 27. Bagian OHnya pindah Keduanya akan berikatan karena bagian 4OSO3 yang menjadi H2SO bermuatan negatif sudah berikatan dengan H Alcohols
- 28. 3. Addition of Reagents to aldehydes and ketones H+ Ikatan double bond OMgX akan menjadi putus. Bagian R akan OH saat bereaksi pindah ke C. Bagian MgX akan pindah ke O Alcohols
- 29. Primary Alcohols Obtained by treating Grignard reagents with formaldehyde H+ Ikatan double bond putus. Bagian R akan OMgX akan menjadi pindah ke C. Bagian OH saat bereaksi MgX akan pindah ke O Alcohols
- 30. Secondary Alcohols Obtained by treating Grignard reagents with other aldehyde H+ Ikatan double bond putus. Bagian R akan OMgX akan menjadi pindah ke C. Bagian OH saat bereaksi MgX akan pindah ke O Alcohols
- 31. Tertiary Alcohols Obtained by treating Grignard reagents with ketones H+ Ikatan double bond putus. Bagian R akan OMgX akan menjadi pindah ke C. Bagian OH saat bereaksi MgX akan pindah ke O Alcohols
- 34. 5. Reduction of acids with lithium aluminium hydride (LiAlH4) Setelah bereaksi ikatan double bond dan O hilang Alcohols
- 35. 6. Acid-hydrolysis of esters Keduanya akan bereaksi OH akan pindah sehingga menjadi C3H7OH asam akan membentuk asetat Alcohols
- 36. Important Individual Alcohols Methanol (methyl alcohol, wood alcohol). In industry, it is used as the raw material for making formaldehyde, as a solvent, and as a denaturant. Ethanol (ethyl alcohol, grain alcohol). In industry ethanol is used as a solvent and to prepare perfumes, lotions, and rubbing compound. 2-propanol (isopropyl alcohol) otu used as a disinfectant Alcohols
- 37. Important Individual Alcohols 1,2-ethanediol (ethylene glycol) and 1,2- propanediol (propylenglycol) are components in permanent type antifreezes. 1,2,3-propanetriol (glycerol, glycerin) it used as afood additive to help keep food moist Sugars. All carbohydrates consist of polyhydroxy compounds Alcohols
- 38. Thank You