The altrose is a kind of the monosaccharide classified into the aldohexose.
It is an epimer in 3rd place of the mannose.

･It hardly melts to the methanol though it melts to water.
･The isomerization is caused in solution, and it becomes a compound with the ring-shaped structure (mutarotation).
It is β-pyranose form it reaches the condition of equilibrium that the existence ratio is the highest.