GRADUATE ORGANIC CHEMISTRY (VOLUME - I)

Size: px

Start display at page:

Download "GRADUATE ORGANIC CHEMISTRY (VOLUME - I)"

Ethelbert Morgan
5 years ago
Views:

1 GRADUATE ORGANIC CHEMISTRY (VOLUME - I) (for B.Sc. Ist year students of U.P. (Unified), GNDU, Panjab, Punjabi, MDU, KU, Himachal, Jammu, Kashmir and other Indian Universities) (Strictly as per new syllabus and UGC curriculum) Dr. M.K. JAIN M.Sc., Ph.D. (Glasgow) Former Professor, National Dairy Research Institute (Deemed University), KARNAL (Haryana) Dr. FATEH BAHADUR M.Sc., Ph.D. Former-Head, Department of Chemistry K.N. Govt. P.G. College Gyanpur, Sant Ravidas Nagar, BHADOHI (U.P.) Dr. S.C. SHARMA M.Sc., Ph.D., Danida fellow Former-Head, Department of Chemistry V.B.R.I. P.G. College, UDAIPUR (Rajasthan) 3 rd REVISED EDITION Future for WINNERS VISHAL PUBLISHING CO. JALANDHAR - DELHI

2 CONTENTS UNIT I 1. STRUCTURE AND BONDING Introduction (1) 1.1. Hybridization (2) Types of Hybridization (2) Types of Covalent Bonds (8) 1.2. Bond-Length (9) 1.3. Bond Angles (11) 1.4. Bond Energies (Bond Strengths) (12) 1.5. Localized and Delocalized Chemical Bonds (13) 1.6. Van Der Waals Interactions Or London Forces (16) 1.7. Inclusion Compounds (18) 1.8. Charge-Transfer Complexes (19) 1.9. Inductive Effect / Transmission Effect (20) Application of Inductive Effect (21) Field Effect (22) Electomeric Effect (22) Resonance (24) Applications of Resonance (26) Mesomeric Effect (28) Hyperconjugation (29) Aromaticity (Hückel's Rule) (33) Hydrogen Bonding (34) Types of Hydrogen Bonding (34) Effect of Hydrogen Bonding (36) Summary (38) Questions and Problems (43) 2. MECHANISM OF ORGANIC REACTIONS Introduction (49) 2.1. Notations Used In Organic Chemistry (49) Curved Arrow Notation (49) Half Headed Arrow (Fish-hook arrow )(50) Double Headed Arrow (50) Straight Arrow Notation (50) 2.2. Homolytic and Heterolytic Bond Breaking (Fission of Bond) (50) 2.3. Types of Reagents (51) Electrophilic reagents or electrophiles(51) Nucleophilic reagents or nucleophiles (52) Free radicals (53) 2.4. Types of Organic Reactions (53) E 1 Mechanism (Unimolecular Mechanism)(57) E 2 Mechanism (Bimolecular Mechanism) (58) 2.5. Reactivity Rates of Reaction and Energy Profile (Energy Consideration) (59) Energy Changes During The Reactions (61) 2.6. Reactive Intermediates (63) Carbocations or Carbonium Ions (63) Formation of Carbocations (66) Reactions of Carbocations (66) Carbanions (67) Formation of Carbanions (67) Structure (68) Stability of Carbanion (68) Reactions of Carbanion (70) Carbon Free Radicals (70) Structure (71) Stability (71) Long Life Radicals (73) Carbenes (74) Nitrenes (75) Benzynes / Arynes (76) 2.7. Assigning Formal Charges on Intermediates and Other Ionic Species (80) 2.8. Methods of Determination of Reaction Mechanism (80) Product analysis (identification of products) (80) Determination of the presence of intermediates (81) Isotopic labelling (83) Isotope effect (83) Stereochemical evidence (84) Kinetic evidence (85) Summary (85) Questions and Problems (89) 3. ALKANES (SATURATED HYDROCARBONS) Introduction (97) 3.1. IUPAC Nomenclature of Unbranched Alkanes (97) 3.2. IUPAC Nomenclature of Branched Chain Alkanes (97) 3.3. The Alkyl Groups (100) 3.4. Classification of Carbon Atoms In Alkanes (100) 3.5. Isomerism in Alkanes (101) 3.6. General Methods of Preparation (101) From Decarboxylation of aliphatic monocarboxylic acids. (Lab. method) (101) Kolbe s Electrolytic method (102) From Alkyl Halide (103) By Reduction (103) By Wurtz Reaction (103) By Frank Land s Method (104)

3 From Hydrogenation of alkenes (104) Corey-House Synthesis (104) 3.7. General Properties (105) Physical Properties (105) Chemical Properties (106) Orientation in Halogenation of Alkanes (109) Questions and Problems (113) 4. CYCLOALKANES (ALICYCLIC COMPOUNDS) Introduction (118) 4.1. Nomenclature (118) 4.2. Occurrence (119) 4.3. General Methods of Preparation / Formation (119) 4.4. Properties (123) General Physical Properties (123) Chemical Properties (124) 4.5. Stability of Cycloalkanes (125) Baeyer's Strain Theory (125) Limitation of Baeyer's Strain Theory (126) Sachse-Mohr Theory of Stainless Rings (127) Molecular Orbital Theory of Angle Strain (128) Cyclopropane (Banana Bond) (128) Questions and Problems (129) UNIT II 5. STEREOCHEMISTRY OF ORGANIC COMPOUNDS Introduction (131) 5.1. Types of Isomerism (131) Structural Isomerism (131) Stereoisomerism (134) Geometric Isomerism (134) Compounds Showing Geometric Isomerism (135) Compounds Showing No Geometric Isomerism (135) Cause of Geometric Isomerism in Alkenes (136) Geometric Isomerism of Maleic and Fumaric Acids (136) Determination of Configuration of Geometric Isomers (137) E and Z system of Nomenclature For Geometric Isomers (138) Geometric Isomerism in Oximes (140) Determination of Configuration of Oximes (141) Geometric Isomerism in Alicyclic Compounds (143) Optical Isomerism (144) Cause of Optical Activity (144) Asymmetric Carbon Atom (144) The Chiral Centre or Stereogenic Centre/ Molecular Chirality (144) Tests For Chirality : Plane of Symmetry (145) Elements of Symmetry (146) Enantiomers (147) Properties of Enantiomers (147) Compounds with Two Dissimilar Stereogenic Centres (148) Diastereomers (148) Properties of diastereoisomers (148) Erythro and Threo Configurations (149) Optical Isomerism in Compounds containing Two Similar Stereogenic Centres (149) Meso Compounds (149) Configuration (151) Relative and Absolute Configuration (151) D and L System of Nomenclature!151) Absolute Configuration (152) R and S System of Nomenclature (152) Sequence Rules (152) Assignment of R-S Configuration to two or more Assymmetric Carbon Atoms (154) Configuration of Molecules with one Asymmetric Carbon Atom (155) Compounds Containing two Asymmetric Carbon Atoms (156) External and Internal Compensation (157) Racemisation (157) Inversion of Configuration (Walden Inversion) (158) Retention of Configuration (159) Resolution of Enantiomers (159) Conformational Isomerism (161) Conformation of Ethane (161) Conformation of n-butane (162) Conformation of Cyclohexane (165) Equatorial and Axial Bonds in Cyclohexane (166) Conformation of Monosubstituted Cyclohexane (167) Conformations of Disubstituted Cyclohexanes (168)

4 Fischer Projection Formulas (169) Sawhorse Representation (170) Newman Projection Formula (170) Flying Wedge Formula (170) Differences Between Conformation and Configuration (171) Questions and Problems (172) UNIT III 6. ALKENES Introduction (182) 6.1. Nomenclature (182) 6.2. General Methods of Preparation / Formation (184) 6.3. Orientation in Elimination Reaction (188) Saytzeff Rule (188) Hofmann Rule (Hofmann elimination) (191) 6.4. Relative Stabilities of Alkenes (194) 6.5. Properties of Alkenes (196) Physical Properties (196) Chemical Properties (196) Addition Reaction (197) Electrophilic Addition Reactions (198) Addition of Symmetrical Reagent (198) Addition of Halogen Acids (201) Markownikoff's Rule (201) Rearrangement of Carbocations (205) Addition of Hypochlorous Acid (207) Addition of Sulphuric Acids (207) Addition of Water (207) Hydroboration-Oxidation (208) Hydration by Oxymercuration- Demercuration (209) Alkylation (211) Oxidation Reactions (211) Polymerization (214) Substitution Reaction (Halogen substitution) (216) 6.6. Location of Double Bond in Alkene (217) 6.7. Industrial Applications (217) Ethylene, Ethene (217) Propene or Propylene (218) Questions and Problems (218) 7. ALKADIENES Introduction (227) 7.1. Nomenclature (227) 7.2. Classification of Dienes (227) 7.3. Structure of Allene (228) 7.4. Structure of 1,3-Butadiene (229) Relative Stability of Dienes (230) 7.5. General Methods of Preparation / Formation (231) 7.6. Properties (232) Physical Properties (232) Chemical Properties (232) Addition of Halogens (232) Addition of Halogen Acids (234) 1,2-versus 1,4-Addition of Conjugated Dienes (Rate versus equilibrium) (235) Addition of HBr to isolated diene (238) Addition of HBr to asymmetric conjugated diene (238) Diels-Alder Reaction (4+2) Cycloaddition (239) Stereochemistry of the Diels-Alder Reaction (240) Conformations of the Diene (241) Questions and Problems (245) 8. CYCLOALKENES Introduction (252) 8.1. Nomenclature (252) 8.2. Method of Formation / Preparation (253) 8.3. Chemical Reactions (254) 8.4. Conformation of Cycloalkenes (258) Questions and Problems (259) 9. ALKYNES Introduction (261) 9.1. Nomenclature (261) 9.2. Structure and Bonding in Alkynes (263) 9.3. General Methods of Formation / Preparation (263) 9.4. Physical Properties (266) 9.5. General Reactions of Alkynes (267) Electrophilic addition reactions (267) Nucleophilic addition reactions (270) Reaction due to acetylenic proton (272) Reduction reactions (272) Oxidation reactions (273) Polymerization (275) Isomerization reactions of Alkynes (276) 9.6. Acidity of Alkynes (276) Hybridization Method (277) Electronegativity Method (277) Acidic Character of Terminal Alkynes (278) Cause of Acidity of Terminal Alkynes (279) Questions and Problems (280)

5 UNIT IV 10. ARENES AND AROMATICITY [I] Introduction (288) Nomenclature of Benzene Derivatives (288) The Aryl Groups (291) The Aralkyl Groups (291) Aromatic Nucleus and Side-Chain (291) Structure of Benzene (291) Resonance Structure Theory (Valence Bond Theory) (294) Molecular Orbital Stucture of Benzene (294) Aromaticity (Hückel s Rules) (296) Heterocyclic Aromatic Compounds (297) Antiaromaticity (299) Questions and Problems (299) 11. ARENES AND AROMATICITY [II] Introduction (300) Electrophilic Aromatic Substitution (301) General Mechanism (301) Role of and -complexes in aromatic electrophilic substitution (302) Halogenation (303) Nitration (304) Sulphonation (305) Fridel-Crafts Reaction (306) Mercuration (308) Aromatic Electrophilic Substitution Unimolecular (ArS E 1 ) (309) Addition Reactions (309) Addition of Hydrogen (309) Birch Reduction (310) Addition of halogens (311) Oxidation Reactions (311) Orientation in Aromatic Ring (312) Rules of Orientation (312) Effect of Substituents on Reactivity (Activating & Deactivating Groups) (314) Theory of Effect of Substitutents on Reactivity and Orientation (315) Introduction of a Third Group into the Benzene Ring (321) Benzene Homologues (Arenes) (324) Alkyl Benzenes (325) Toluene, Methyl benzene, C 6 H 5 CH 3 (325) Cumene (isopropyl benzene) (328) Xylenes (Dimethyl Benzenes) (329) Alkenyl Benzene (331) Alkynyl Benzene (Phenylacetylene) (332) Diphenyl (Biphenyl), Phenylbenzene (333) Naphthalene (335) Anthracene (339) Questions and Problems (342) 12. ALKYL HALIDES Inroduction (349) Classification of Monohaloalkanes (350) Nomenclature (350) Methods of Formation / Preparation (350) Physical Properties (352) Chemical Properties (353) (A) Nucleophilic Substitution Reaction (354) Factors influencing S N 1 and S N 2 reactions (361) S N i -Mechanism (363) (B) Elimination Reactions (367) (C) Other Reactions (368) Polyhalogen Compounds (370) Chloroform, Trichloro Methane (370) Tetra Haloalkanes (375) Chlorofluoro Hydrocarbons (Freons) (376) Questions and Problems (377) 13. AROMATIC HALOGEN COMPOUNDS Introduction (381) Addition Compounds (381) Benzene Hexachloride, B.H.C. (381) Nuclear Halogen Compounds (Aryl Halides) (382) Methods of Preparation / Formation (382) Properties (385) (A) Physical Properties (385) Relative Reactivities of Aryl Halides vs. Alkyl Halides and Aralkyl Halides (386) (B) Chemical Properties (389) Dichloro Diphenyl Trichloro Ethane or D.D.T. (394) Arylalkyl Halides (395) Properties (Physical) (396) Questions and Problems (399) 14. VINYL AND ALLYL HALIDES Unsaturated Aliphatic Halides (408) Vinyl Chloride (Chloro ethene) (408) Comparative Reactivity of Alkyl Halide and Vinyl Halide Towards Nucleophilic Substitution (409) Allyl Iodide, 3-Iodo-1-Propene (410) Questions and Problems (414)

Fundamentals of. Organic Chemistry. for. [Second Year B.Sc. (Main) Students of M.G. University, Kerala] III Semester

Fundamentals of. Organic Chemistry. for. [Second Year B.Sc. (Main) Students of M.G. University, Kerala] III Semester Fundamentals of Organic Chemistry for [Second Year B.Sc. (Main) Students of M.G. University, Kerala] III Semester (This Book is an outcome of Modern Organic Chemistry by M.K. Jain & S.C. Sharma duly recommended