Modern Methods in Stereoselective Aldol Reactions

The selective formation of bondings between molecules is one of the major challenges in organic chemistry, and the so-called aldol reaction is one of the most important for this purpose. These reactions are a highly useful tool for developing such novel substances as natural products and pharmaceuticals. Likes its highly successful and much appreciated predecessor, "Modern Aldol Reactions", this ready reference provides a systematic overview of methodologies for installing a required configuration during an aldol addition step, but shifts the focus so as to cover the latest developments. As such, it presents a set of brand new tools, including vinylogous Mukaiyama-aldol reactions and substrate-controlled aldol reactions, as well as asymmetric induction in aldol additions. Furthermore, new developments in existing stereoselective aldol additions are described, such as the deployment of supersilyl groups or organocatalyzed aldol additions. All of these methodologies are presented in the context of their deployment in the total synthesis of natural products.

Table of Contents:
Preface STEREOSELECTIVE ACETATE ALDOL REACTIONS Introduction Mukaiyama Aldol Reaction Metal Enolates Conclusions THE VINYLOGOUS MUKAIYAMA ALDOL REACTION IN NATURAL PRODUCT SYNTHESIS Introduction Aldehyde-Derived Silyl Dienol Ethers Ester-Derived Silyl Dienol Ethers Amide-Derived Silyl Dienol Ethers - Vinylketene Silyl N,O-Acetals Acyclic Acetoacetate-Derived Silyl Dienolates - Chan's Diene Cyclic Acetoacetate-Derived Dienolates Furan-Derived Silyloxy Dienes Pyrrole-Based 2-Silyloxy Dienes Comparison with Other Methods ORGANOCATALYZED ALDOL REACTIONS Introduction Proline as Organocatalyst Proline Derivatives as Organocatalysts Conclusions and Outlook SUPERSILYL PROTECTIVE GROUPS IN ALDOL REACTIONS Introduction Aldol Addition with Acetaldehyde-Derived Super Silyl Enol Ether Alpha-Substituted Silyl Enol Ethers Derived from Aldehydes Aldol Addition to Chiral Aldehydes One-Pot Sequential Aldol Reactions Sequential Aldol-Aldol Reactions of Acetaldehyde Double Aldol Reactions with Alpha-Substituted Silyl Enol Ethers Stereochemical Considerations Aldol Reactions of Beta-Supersiloxy Methyl Ketones Total Synthesis of Natural Products Using Supersilyl Aldol Reactions Conclusion and Outlook ASYMMETRIC INDUCTION IN ALDOL ADDITIONS Introduction Asymmetric Induction Using Chiral Ketones Asymmetric Induction Using Chiral Aldehydes Asymmetric Induction in the Aldol Addition of Chiral Enolates to Chiral Aldehydes POLYPROPIONATE SYNTHESIS VIA SUBSTRATE-CONTROLLED STEREOSELECTIVE ALDOL COUPLINGS OF CHIRAL FRAGMENTS Introduction Principles of Stereoselective Aldol Reactions Stereoselective Aldol Coupling of Chiral Reactants 2-Alkoxyalkyl Ethyl Ketones: 2-Desmethyl Polypropionate Equivalents Conclusions APPLICATION OF OXAZOLIDINETHIONES AND THIAZOLIDINETHIONES IN ALDOL ADDITIONS Introduction Preparation of Oxazolidinethione and Thiazolidinethione Chiral Auxiliaries Acylation of Oxazolidinethione and Thiazolidinethione Chiral Auxiliaries Propionate Aldol Additions Acetate Aldol Additions Glycolate Aldol Additions ENZYME-CATALYZED ALDOL ADDITIONS Introduction Pyruvate Aldolases N-Acetylneuraminic Acid Aldolase (NeuA) Dihydroxyacetone Phosphate (DHAP) Aldolases D-Fructose-6-Phosphate Aldolase and Transaldolase B Phe178Tyr: FSA-Like Aldolases 2-Deoxy-D-Ribose-5-Phosphate Aldolase (RibA or DERA) Glycine/Alanine Aldolases Aldol Reactions Catalyzed by Non Aldolases Conclusions and Perspectives Index

About the Author :
Born in 1950, Rainer Mahrwald studied chemistry at MLU Halle and subsequently joined the "Manfred von Ardenne" Research Institute in Dresden, where he led the synthetics group. He gained his doctorate under G. Wagner in Leipzig in 1979, and went on to the Institute of Organic Chemistry at the Academy of Science in Berlin, where he remained until 1990. Following a stay at the Philipps-University in Marburg, Dr. Mahrwald qualified as a lecturer at the Humboldt University Berlin, where he is now full professor.