Ketene Dithioacetals in Organic Synthesis: Recent Developments

All articles of this category Ketene dithioacetals are reviewed as versatile building blocks in a multitude of synthetically useful transformations. After discussing the methods for preparation of ketene dithioacetals, their application in cyclizations, C-C bond formation and in the synthesis of heterocyclic systems will be described. Their use as carboxyl equivalents, which display an umpolung-type reactivity pattern will be emphasized. 1 Introduction 2.Synthesis of Ketene Dithioacetals 2.1. Synthesis of Nonfunctionalized Ketene Dithioacetals 2.1.1. From Aldehydes and Ketones by Olefination 2.1.2. From Esters or Ester Equivalents 2.1.3. From Dithioacetals 2.1.4 From 1,1-Dihetero Substituted Olefins 2.2. Synthesis of Polyfunctional Ketene Dithioacetats 3. Ketene Dithioacetals in Organic Synthesis 3.1. a 1 ,d 2 ,a 3 ... : Normal Reactivity 3.2. d 1 , a 2 , d 3 ...: Umpolung-Type Reactivity 3.3. Polyfunctional Ketene Dithioacetals in Organic Synthesis 3.3.1.α-Oxo Ketene Dithioacetals 3.3.2. Nitro Ketene Dithioacetals 3.3.3. Miscellaneous 4. Conclusion