xii Contents 13-12 Carbon-13 NMR Spectroscopy 602 13-13 Interpreting Carbon NMR S ectra 609 13-14 Essential Terms 617 Study Problems 618 14 ETHERS,EPOXIDES,AND THIOETHERS 625 14-1 Introduction 625 14.2 Physical Properties of Ethers 626 14-3 Nomenclature of Ethers 630 14-4 Spectroscony of Ethers 633 14-5 The Williamson Ether Synthesis 635 14-6 Synthesis of Ethers by Alkoxymercuration-Demercuration 636 14-7 Industrial Synthesis:Bimolecular Condensation of Alcohols 637 Summary:Syntheses of Ethers(Review)638 14-8 Cleavage of Ethers by HBr and HI 638 Mechanism 14-1:Cleavage of an Ether by HBr or HI 639 14-9 Autoxidation of Ethers 641 Summary:Reac ons of Ethers 641 Thioethers(Sulfid Synthesis Epo 8g946S1Ehers642 ses 64 14-12 ed Ring g of poxides lyzed Opening of Epoxides Mechanism 14-3:Acid-Catalyzed Opening of an Epoxide in an Alcohol Solution 650 14-13 Base-Catalyzed Ring Opening of Epoxides 652 chanism 1 Base atalyzed Opening of Epoxides 653 Orientation of Epo: de Ring Opening 65 Grignard anc 14.16 xy Resins:The Advent of Modern Glues 656 Summary:Reactions of Epoxides 658 EssentialTerms 660 Study Problems 662 15 CONJUGATED SYSTEMS,ORBITAL SYMMETRY, AND ULTRAVIOLET SPECTROSCOPY 667 15-1 Introduction 667 152 Stabilities of Dienes 667 1 Molecular Orbital Picture of a Conjugated System 669 Allylic C and 1. 67E nto Conj gated Dienes 674 Conjugated Diene nd 1. 675 xii Contents 13-12 Carbon-13 NMR Spectroscopy 602 13-13 Interpreting Carbon NMR Spectra 609 13-14 Nuclear Magnetic Resonance Imaging 611 Problem-Solving Strategy: Spectroscopy Problems 612 Essential Terms 617 Study Problems 618 14 ETHERS, EPOXIDES, AND THIOETHERS 625 14-1 Introduction 625 14-2 Physical Properties of Ethers 626 14-3 Nomenclature of Ethers 630 14-4 Spectroscopy of Ethers 633 14-5 The Williamson Ether Synthesis 635 14-6 Synthesis of Ethers by Alkoxymercuration–Demercuration 636 14-7 Industrial Synthesis: Bimolecular Condensation of Alcohols 637 Summary: Syntheses of Ethers (Review) 638 14-8 Cleavage of Ethers by HBr and HI 638 Mechanism 14-1: Cleavage of an Ether by HBr or HI 639 14-9 Autoxidation of Ethers 641 Summary: Reactions of Ethers 641 14-10 Thioethers (Sulfides) and Silyl Ethers 642 14-11 Synthesis of Epoxides 646 Summary: Epoxide Syntheses 648 14-12 Acid-Catalyzed Ring Opening of Epoxides 649 Mechanism 14-2: Acid-Catalyzed Opening of Epoxides in Water 649 Mechanism 14-3: Acid-Catalyzed Opening of an Epoxide in an Alcohol Solution 650 14-13 Base-Catalyzed Ring Opening of Epoxides 652 Mechanism 14-4: Base-Catalyzed Opening of Epoxides 653 14-14 Orientation of Epoxide Ring Opening 654 14-15 Reactions of Epoxides with Grignard and Organolithium Reagents 656 14-16 Epoxy Resins: The Advent of Modern Glues 656 Summary: Reactions of Epoxides 658 Essential Terms 660 Study Problems 662 15 CONJUGATED SYSTEMS, ORBITAL SYMMETRY, AND ULTRAVIOLET SPECTROSCOPY 667 15-1 Introduction 667 15-2 Stabilities of Dienes 667 15-3 Molecular Orbital Picture of a Conjugated System 669 15-4 Allylic Cations 673 15-5 1,2- and 1,4-Addition to Conjugated Dienes 674 Mechanism 15-1: 1,2- and 1,4-Addition to a Conjugated Diene 675