¹ Source: wiktionary.com
Medical Definition of Hemiketal
1. RC(R')(OH)OR', a product of the addition of an alcohol to a ketone. In the ketose sugars, the hemiketal formation is from an attack by an internal OH on the ketone carbonyl leading to intramolecular cyclization (furanose or pyranose); the hemiketal forms of the sugars are involved in polysaccharide formation, as glycosyls or glycosides. See: hemiacetal, ketal. (05 Mar 2000)