text: Aldehydes participate in many reactions. From the industrial perspective, important reactions are:
  * condensations, e.g., to prepare plasticizers and polyols, and
  * reduction to produce alcohols, especially "oxo-alcohols". From the biological perspective, the key reactions involve addition of nucleophiles to the formyl carbon in the formation of imines (oxidative deamination) and hemiacetals (structures of aldose sugars).