6. Anhydrosugars

The anhydrosugars are reviewed in this chapter. The emphasis is placed on the general methodology of their preparation, as well as, their application in stereocontrolled organic synthesis. The material is divided into two main parts: anomeric anhydrosugars and non-anomeric ones. In the first class, 1,2-sugar epoxides and 1,6‑anhydrosugars are the most important since they offer significant synthetic potential in targeted synthesis of important compounds. From the second class, sugar epoxides (2,3- and 3,4‑oxiranes) are particularly useful. The synthesis of both classes of anhydrosugars (anomeric and non-anomeric) is illustrated by selected examples including older examples (i. e. those described also in the previous edition of this monograph) and those published more recently. Various methods for the preparation of anhydrosugars are described in order to give the reader a general impression of the importance of such derivatives both as biologically active targets (illustrated by selected examples of anhydronucleosides) and optically pure building blocks in targeted synthesis. The material included in this chapter should help the reader solve any problems faced in their laboratories connected with planning and execution of the synthesis of optically pure targets.