Hemiacetal

In organic chemistry, a hemiacetal or a hemiketal has the general formula R¹R²C(OH)OR, where R¹, R² is hydrogen or an organic substituent. They generally result from the addition of an alcohol (a compound with at least one −OH group) to an aldehyde (R−CH=O) or a ketone (R₂C=O), although the latter are sometimes called hemiketals. Most sugars are hemiacetals.