Deoxy Sugars: Occurrence and Synthesis

Abstract

Publisher Summary This chapter describes the occurrence and synthesis of deoxy sugars. Several deoxy sugars, notably 2-deoxy- D -erythro-pentose (2-deoxy- D -ribose)—the sugar component of DNA, 6-deoxy- L -mannose ( L -rhamnose), 6-deoxy- L -galactose ( L -fucose), 6-deoxy- D -glucose (quinovose), and their derivatives, occur very widely in natural product. The iodo and bromo derivatives of monosaccharides can be reduced by a variety of reducing agents to afford the corresponding deoxy sugar. The more stable chloro derivatives can be reduced with Raney nickel. Selective reduction of a secondary chloride with respect to a primary chloride may be achieved if the reduction is performed in the presence of triethylamine. Mesylates or tosylates may be reduced directly or through the intermediate halides or epoxides. Epoxides are involved in the reduction of tosylates by lithium aluminum hydride or lithium triethyl borohydride. A general method for the synthesis of 2-deoxyaldoses utilizes a reaction sequence involving the formation and subsequent reduction of ketene dithioacetal intermediates.