1,2-Amino Alcohols and Their Heterocyclic Derivatives as Chiral Auxiliaries in Asymmetric Synthesis

Modern Methods of Monosaccharide Synthesis from Non-Carbohydrate Sources.

Synthesis of (4S)-hydroxymethyl-(2R)-(2-propyl)-butyrolactone: A quest for a practical route to an important hydroxyethylene isostere chiron

Full details are provided for an exceedingly practical method to synthesize d- and l-α-amino acids, N-protected α-amino acids, and N-methyl-α-amino acids, employing as a key step the asymmetric alkylation of pseudoephedrine glycinamide (1) or pseudoephedrine sarcosinamide (2). Practical procedures for the synthesis of 1 and 2 from pseudoephedrine and glycine methyl ester or sarcosine methyl ester, respectively, are presented. Optimum protocols for the enolization and subsequent alkylation of 1 and 2 are described. Alkylation reactions of 1 and 2 are found to be quite efficient with a wide range of alkyl halide substrates, and the products are formed with high diastereoselectivity. The products of these alkylation reactions are hydrolyzed efficiently and with little to no racemization simply by heating in water or water−dioxane mixtures. This protocol provides an exceedingly practical method for the preparation of salt-free α-amino acids of high enantiomeric purity. Alternatively, the alkylation products m...

Highly Practical Methodology for the Synthesis of d- and l-α-Amino Acids, N-Protected α-Amino Acids, and N-Methyl-α-amino Acids

This chapter discusses the various methods for the preparation of oxabicyclic compounds, with an emphasis on the stereo- and enantioselective synthesis of these substances. Methods to desymmetrize meso oxabicyclic compounds are also presented. The utility of these substrates for organic synthesis is demonstrated by the many strategies available for ring-opening the bicyclic compounds to yield cyclic and acyclic structures. Examples demonstrating how this strategy has been incorporated into the efficient syntheses of many natural products are presented.

Using Ring-Opening Reactions of Oxabicyclic Compounds as a Strategy in Organic Synthesis

Introduction Nomenclature Why Asymmetric Synthesis? Methods to Achieve Asymmetric Synthesis Resolution A Question of Scale General Rules Carbonyl Additions Houk's Rule Allylic Strain Baldwin's Rules Pericyclic Transition States One-Carbon Transformations Inversions at a Single Carbon Center Chiral Organometallic Reagents Other Reactions Reactions With Carbonyl Compounds Reactions of Carbonyl Compounds With Nucleophiles Acetal Reactions Other Electrophiles Other Reactions Reductions Enolate Reactions of Carbonyl Compounds Enol Ethers and Enolate Formation Reactions of Enol Ethers and Enolates Use of Nitrogen Derivatives Asymmetric Deprotonations and Protonations Reactions of Functionalized Carbonyl Systems Alkylations of 1,2-Functionalized Carbonyl Compounds Reductions of 1,2-Functionalized Carbonyl Compounds Alkylations of 1,3-Functionalized Carbonyl Compounds Reductions of 1,3-Functionalized Carbonyl Compounds Other Systems Aldol and Related Reactions The Aldol Reaction: Methods of Control The Aldol Reaction: The Role of Enolate Geometry and Metal Counterion The Formose Reaction Preparation and Reactions of Alkenes Alkene Synthesis Reactions of Alkenes Reactions of Functionalized Alkenes Hydrogenations Other Transition Metal Catalyzed Reactions Hydride Delivery Agents Reactions of Some Functionalized Alkenes Conjugate Additions Allyl Alkylations Other Reactions Asymmetric Oxidations of Isolated Alkenes Epoxidations Reactions of Epoxides 1,2-Diols Formation and Reactions of Cyclic Sulfates Preparation and Reactions of Aziridines Oxidations of Functionalized Alkenes Epoxidation of Allyl Alcohols Reactions of 2,3-Epoxy Alcohols and Related Systems Epoxidations and Reactions of Other Unsaturated Systems Other Oxidations Other Systems Pericyclic Reactions The Diels-Alder Reaction Claisen Rearrangements Ene Reaction Dipolar Cycloadditions [2,3] Sigmatropic Rearrangements Photochemical Reactions Other Reactions Cyclization Reactions and Reactions of Cyclic Systems Carbocycles Preparations of Lactones and Cyclic Ethers Reactions of Lactones and Related Systems Reactions of Cyclic Sulfur Compounds Biochemical Methods Esters and Related Compounds Reductions Other Reactions Catalytic Antibodies Index

Asymmetric Synthetic Methodology

The synthesis of carbohydrate derivatives from acyclic precursors

Methodology to establish 1,2- and 1,3-difunctionality for the synthesis of carbohydrate derivates

Studies on the alkylation of dipeptide substrates

The 7-oxabicyclo[2.2.1]heptanyl system provides a rapid entry to carbohydrate derivatives in a stereoselective manner by virtue of the rigid framework. The formation of this bicyclic system through a Diels-Alder reaction of furan with a number of dienophiles is influenced by the substitution on the dienophile. Use of an anion stabilising group as a carbonyl equivalent has previously led to a ring opening reaction of the bicyclic system. However, anion chemistry can be used to functionalise the bicyclic system, and used for the introduction of a hydroxy group that allows, in turn, a method for the preparation of hexose derivatives

David J. Ager

Papers

Asymmetric Synthetic Methodology

The synthesis of carbohydrate derivatives from acyclic precursors

Methodology to establish 1,2- and 1,3-difunctionality for the synthesis of carbohydrate derivates

Studies on the alkylation of dipeptide substrates

Development of methodology based on the use of the 7-oxabicyclo[2.2.1]heptanyl system for the preparation of carbohydrate derivatives