Page 25 - Advanced Organic Chemistry Part B - Reactions & Synthesis

6.2. 1,3-Dipolar Cycloaddition Reactions........................................................... 526 xxvii
6.2.1. Regioselectivity and Stereochemistry............................................... 528
Contents
6.2.2. Synthetic Applications of Dipolar Cycloadditions........................... 531
6.2.3. Catalysis of 1,3-Dipolar Cycloaddition Reactions ........................... 535
6.3. [2 + 2] Cycloadditions and Related Reactions Leading
to Cyclobutanes ............................................................................................ 538
6.3.1. Cycloaddition Reactions of Ketenes and Alkenes............................ 539
6.3.2. Photochemical Cycloaddition Reactions........................................... 544
6.4. [3,3]-Sigmatropic Rearrangements............................................................... 552
6.4.1. Cope Rearrangements........................................................................ 552
6.4.2. Claisen and Modified Claisen Rearrangements................................ 560
6.5. [2,3]-Sigmatropic Rearrangements............................................................... 581
6.5.1. Rearrangement of Allylic Sulfoxides, Selenoxides,
and Amine Oxides............................................................................. 581
6.5.2. Rearrangement of Allylic Sulfonium and Ammonium Ylides......... 583
6.5.3. Anionic Wittig and Aza-Wittig Rearrangements ............................. 587
6.6. Unimolecular Thermal Elimination Reactions............................................. 590
6.6.1. Cheletropic Elimination..................................................................... 591
6.6.2. Decomposition of Cyclic Azo Compounds ...................................... 593
6.6.3. -Eliminations Involving Cyclic Transition Structures.................... 596
Problems ............................................................................................................... 604

Chapter 7. Organometallic Compounds of Group I and II Metals ....... 619

Introduction........................................................................................................... 619
7.1. Preparation and Properties of Organomagnesium
and Organolithium Reagents........................................................................ 620
7.1.1. Preparation and Properties of Organomagnesium Reagents ............ 620
7.1.2. Preparation and Properties of Organolithium Compounds .............. 624
7.2. Reactions of Organomagnesium and Organolithium Compounds.............. 634
7.2.1. Reactions with Alkylating Agents .................................................... 634
7.2.2. Reactions with Carbonyl Compounds .............................................. 637
7.3. Organometallic Compounds of Group IIB and IIIB Metals ....................... 650
7.3.1. Organozinc Compounds.................................................................... 650
7.3.2. Organocadmium Compounds............................................................ 661
7.3.3. Organomercury Compounds ............................................................. 662
7.3.4. Organoindium Reagents.................................................................... 663
7.4. Organolanthanide Reagents.......................................................................... 664
General References............................................................................................... 666
Problems ............................................................................................................... 667

Chapter 8. Reactions Involving Transition Metals....................... 675

Introduction........................................................................................................... 675
8.1. Organocopper Intermediates......................................................................... 675
8.1.1. Preparation and Structure of Organocopper Reagents ..................... 675
8.1.2. Reactions Involving Organocopper Reagents
and Intermediates............................................................................... 680