The Synthesis and Glycosidation of N-Acetylneuraminic Acid

A review on N-acetylneuraminic acid is presented in two parts. The first section details the literature on the total synthesis of Neu5Ac. The second part deals with the progress on the chemical and enzymatic glycosidation of sialic acid. 1. Introduction 1.1. Isolation and Characterization of Sialic Acids 1.2. Biological Significance of Sialic Acids 2. Synthesis of N-Acetylneuraminic Acid 2.1. Enzymatic Methods 2.2. Chemical Synthesis 3. Synthesis of Sialyl Glycosides 3.1. Background 3.2. Synthesis of Simple Glycosides of N-Acetylneuraminic Acid 3.3. The Koenigs-Knorr Method 3.3.1. Primary Alcohols of Carbohydrates as Glycosyl Acceptors 3.3.2. Secondary Carbohydrate Alcohols as Glycosyl Acceptors 3.4. Newer Methods of Sialyl Glycoside Synthesis 3.4.1. Enzymatic Methods 3.4.2. Wittig Method 3.4.3. Directing Auxiliaries at C3 3.4.4. Carboxylic Acid Surrogates in Sialyl Glycoside Synthesis 3.4.5. Thioglycosides as Sialyl Donors 4. Future Prospects