Thiiranes and Thiirenes: Fused-ring Derivatives

1.06 Thiiranes and Thiirenes: Fused-ring Derivatives SCOTT R. HARRING and TOM LIVINGHOUSE Montana State University, Bozeman, MT, USA 1.06.1 INTRODUCTION

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1.06.1.1 Historical Perspective 1.06.1.2 Nomenclature

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1.06.2 THERMODYNAMIC ASPECTS 1.06.2.1 Physical Properties and Physical Constants 1.06.2.2 Thermodynamic Stability and Ring Strain 1.06.2.3 Conformational Analysis

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1.06.3 EXPERIMENTAL STRUCTURAL METHODS 1.06.3.1 NMR Spectroscopy 1.06.3.2 Infrared, Raman, Ultraviolet, and Microwave Spectroscopy 1.06.3.3 X-ray Crystallography

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1.06.4 REACTIVITY OF THE THREE-MEMBERED RING 1.06.4.1 Oxidation of Sulfur 1.06.4.2 Reduction of Sulfur 1.06.4.3 Reactions of the Three-membered Ring with Electrophiles 1.06.4.4 Reactions of the Three-membered Ring with Nucleophiles

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1.06.5

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CYCLOADDITIONS INVOLVING THIIRANES AND THIIRENES

1.06.5.1 [2 + 2] and [4 + 2] Cycloadditions 1.06.5.2 1,3-Dipolar Cycloadditions 1.06.5.3 Synthesis of Fused-ring Thiirenes via Cycloadditions 1.06.6 PHOTOCHEMICAL PROCESSES INVOLVING THIIRANES 1.06.6.1 Photolysis of Thiophenes 1.06.6.2 Cycloadditions of Dewar Thiophenes 1.06.6.3 Miscellaneous Photolytic Reactions Involving Thiiranes

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1.06.7

SYNTHESIS OF FUSED-RING THIIRANES AND THIIRENES

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1.06.8

USES OF FUSED-RING THIIRANES AND THIIRENES

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1.06.1 INTRODUCTION 1.06.1.1

Historical Perspective

Fused-ring thiiranes and thiirenes have received considerably less study than their monocyclic counterparts. The only general review devoted solely to this class of compounds was that which appeared in the first edition of Comprehensive Heterocyclic Chemistry (CHEC-I) <84CHEC-I(7)185>. 241