MORISSON   Organic Chemistry

MORISSON Organic Chemistry


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394
ll.7 The allyl radical as a resonance hybrid 395
I1.8 Stability of the allyl radical 397
11.9 Orbital picture of the allyl radical 397
1 l.l0 Using the resonance theory 399
I I . I I Resonance siabilization of alkyl radicals. Hyperconjugation 40I
ll.l2 The allyl cation as a resonance hybrid 402
I I . 1 3 Nucleophilic substitution in allylic substrates: So,l . Reactivity.
Allylicrearrangement 404
ll.l4 Stabilization ofcarbocations: the resonance effect 406
I l.l5 Nucleophilic substitution in allylic substrates: S"2 407
I 1.16 Nucleophilic substitution in vinylic substrates. Vinylic
cations 407
I l.17 Dienes: structure and properties 409
I I . I 8 Stability of conjugated dienes 410
I 1.19 Resonance in conjugated dienes 411
11.20 Resonance in alkenes. Hyperconjugation 413
ll.2L Ease of formation of conjugated dienes: orientation of
elimination 414
11.22 Electrophriic addition to conjugated dienes. 1,4-Addition 414
11.23 1,2- us. 1,4-Addition. Rate us. equilibrium 417
11.24 Free-radical polymerization of dienes. Rubber and rubber
substitutes 419
I1.25 Isoprene and the isoprene rule 421
11.26 Analysis of dienes 421
l2 Alkynes
l2.l Introduction 425
12.2 Structure of acetyleue. The carbon-carbon triple bond 425
l:.3 Higher alkynes. Nomenclature 428
t 1
t3
CONTENTS
12.4 Physical properties of alkynes 428
12.5 Industrial source of acetylene 429 /
t2.6 Preparation of alkynes 429
122 Reactions of alkynes 430
12.8 Reduction ofSfunes 433
l2.g Electrophilic'addtion to alkynes 434
12.10 Hydration of alkines. TautomeriSm 435
l2.ll Acidity of alkynes. Very weak acids 436
12.12 Reactions of metal acetylides. Synthesis of alkynes 438
12.13 Formation of carbon-carbon bonds. Role played by
organometallic compounds 439
''12.14 Analysis of alkynes 440
Cyclic Aliphatic Compounds
l3.l ,' Open-chain and cyclic compounds 443
l?;2 Nomenclature 443
i3.3 Industriai source 446
13.4 Pleparation 447
13.5 Reactions 448
13.6 Reactions of small-ring compounds. Cyclopropane and
cyclobutane 449 .'
13.7 Baeyer strain theory 450
13.8 Heats of combustion and relative stabilities of the
cycloalkanes 450
139 Orbital picture of angle strain 453
13.10 Factors affecting stabilily.slesnformations 454
-L3,Jl Conformations of cycloalkanes 455
13.12 Equatorial and axial bonds in cyclohexane 460
13.13 Stereoisomerism of cyclic compounds: cis and trans isomers 463
13.14 Stereoisomerism of cyclic compounds. Conformational
analysis 466
13.15 Stereochemistry of elimination from alicyclic compounds 471
13.16 Carbenes. Methylene. Cycloaddition 473
13.17 Addition of substituted carbenes. l,l-Elinination 476
13.18 Cyclic ethers 478
13.19 Crown ethers. Host-guest relationship 478
13.20 Epoxides. Structure and preparation 481
13.21 Reactions of epoxides 482
13:22 Acid-catalyzed cleavage of epoxides. anti-Hydroxylation 483
13.4 Base-catalyzed cleavage of epoxides 485
8.1.4 Orientation of cleavage of epoxides 485
13.25 Analysis of alicyclic compounds 487
14 Aromaticity Benzene
Aliphatic and aromatic compounds 493
Structure of benzene 494
Molecular formula. Isomer number. Kekul6 structure 494
Stability of the benzene ring. Reactions of benzene 497
t4.l
t4.2
r4.3
t4.4
l 5 . l
t5.2
15 .3
15.4
15 .5
15.6
t5.7
15 .8
r 5.9
15 . r0
1 5 . 1 I
t5.r2
1 5 . l 3
15, l4
1 5 . 1 5
1 5 . 1 6
1 5 . 1 7
1 5 . 1 8
1 5 . 1 9
15.20
t5.2r
. i
i 4 . 6
i 1 1
14 .8
14.9
14 .10
1 4 . 1 I
t4 .12
1 4 . 1 3
1 6 . 1
t6.2
1 6 . 3
t6.4
1 6 . 5
1 6 . 6
16.'l
1 6 . 8
1 6 . 9
1 6 . l 0
CONTENTS
Stability of the benzene ring. Heats of hydrogenation and
combustion 498
Carbon-carbon bond lengths in benzene 499
Resonance structure ofbenzene 500
Orbital picture of benzene 501
Representation of the benzene ring 503
Aromatic character. The Hiickel 4n * 2 rule 504
Nomenclature of benzene derivatives 508
Polynuclear aromatic hydrocarbons. Naphthalene 510
Quantitative elemental analysis: nitrogen and sulfur 513
l5 Electrophilic Aromatic Substitution
Introduction 517
Effect of substituent $oups 519
Determination of orientation 520
Determination of relative reactivity 521
Classification of substituent groups 522
Orientation in disubstituted benzenes 522
Orientation and synthesis 524
Mechanism of nitration 525
Mechanism of sulfonation 527
Mechanism of Friedel-Crafts alkylation 528
Mechanism of halogenation 529
Desulfonation. Mechanism of protonation 529
Mechanism of electrophilic aromatic substitution: a
summary fiA
Mechanism of electrophilic aromatic substitution: the two
steps 5 3 I
Reactivity and orientation 535
Theory of reactivity 536
Theory of orientation 5-t8
Electron release via resonance 540
Effect of halogen on electrophilic aromatic substitution 542
Relation to other carbocation reactions 544
Electrophilic substitution in naphthalene 545
The aromatic ring as a substituent 549
Aromatic-aliphatic hydrocarbons: arenes 549
Structure and nomenclature of arenes and their derivatives 551
Physicalproperties 552
Industrial source ofalkylbenzenes 555
Preparation ofalkylbenzenes 556
Friedel-Crafts alkylation 557
Mechanism of Friedel-Ctafls alkylation
Limitations of Friedel-Craffs alkylation
Reactions of alkylbenzenes 561
16 Aromatic-Aliphatic Compounds Arenes and Their
Derivatives
558
561
t 7
CONTENTS
16.l I Oxidation of alkylbenzenes 563
16.12 Electrophilic aromatic substitution in alkylbenzenes 564
16.13 Halogenation of alkylbenzenes: ring a.. side chain 565
16.14 Side-chain halogenationofalkylbenzenes 566
16.15 Resonance stabilization of the benzyl radical 568
16.16 Triphenylmethyl: a stable free radical 570
16.17 Stability of the benzyl cation 574
16.18 Nucleophilic substitution in benzylic substrates 575
16.19 Preparation of alkenylbenzenes. Conjugation with the ring
16.20 Reactions of alkenylbenzenes 578
t6.21 Addition to conjugated alkenylbenzenes 579
16.22 Alkynylbenzenes 580
16.23 Analysis of arenes 580
Spectroscopy and Structure
17.l Determination of structure: spectroscopic methods J85
17.2 The mass spectrum 586
17.3 The electromagnetic spectnrm 589
17.4 The infrared spectrum 590
17.5 Infrared spectra ofhydrocarbons 592
17.6 Infrared spectra ofalcohols 594
17.7 Infrared spectra ofethers 596
17.8 The ultraviolet spectrum 597
17.9 The nuclear magnetic resonanoe (NMR) spectrum 600
17.10 NMR. Number of signals. Equivalent and non+quivalent
protons 601
17.ll NMR. Positions of signals. Chemical shift 604
17.12 NMR. Peak area and proton counting 609
17.13 NMR. Sprtitting of signals. Sprn-sprn coupling 610'
17.14 NMR. Coupling constants 620
17.15 NMR. Complicated spectra. Deuterium labeling 623
17.16 Equivalence of protons: a closer look 625
17.17 Carbon-l3i NMR (CMR) spectroscopy 629
17.18 CMR. Splitting 630
17.19 CMR. Chemical shift 634
17.20 NMR and CMR spectra of hydrocarbons 639
17.21 NMR and CMR spectra of alkyl halides 640
17.22 NMR and CMR spectra of alcohols and ethen. Hydrogen
bonding. Proton exchange 64A
17.23 The electron spin resonance{EsR) spectrum 642
I8 Aldehydes and Ketonee Nucleophilic Addition
Stnrcture 657
Nomenclature 658
Physicalproperties 660
Preparation 661
Preparation of ketqnes by Friedcl{rafts acylation ffi
Pn:paration ofketones by use oforganocopper compounds
576
lE. l
r8.2
lE.3
lE.4
18.5
8.6 668
CONTENTS
Reactions. Nucleophilic addition 669
Oxidation 675
Reduction 677
Addition of cyanide 678
Addition of derivatives of ammonia 679
Addition of alcohols. Acetal formation 680
Cannuzaro reaction 683
Addition of Grignard reagents 685
Products of the Grignard synthesis 686
Planning a Grignard synthesis 688
Syntheses using alcohols 692
Limitations of the Grignard synthesis 695
Tetrahydropyranyl (THP) ethen: the use of a protecting
group 696
Analysis of aldehydes and ketones 697
Iodoform test 697
Analysis of l,2-diols. Feriodic acid oxidation