How is hydroxy(oxo)manganese (2:1) (CAS: 1317-35-7) typically synthesized?

Hydroxy(oxo)manganese (2:1) (CAS: 1317-35-7) is synthesized through the reduction of manganese(IV) oxide with a suitable reducing agent in an aqueous environment. The reaction proceeds via a controlled addition of the reducing agent to maintain the desired 2:1 ratio of hydroxy groups to oxo groups. Yields are typically high, and the reaction is conducted under inert atmosphere to prevent oxidation.