Chemically active (acid-base) extraction

Can you change the solubility property of a compound? How?

Most organic compounds are more soluble in organic solvents than in water,
usually by the distribution coefficient K > 4.

However, specific classes of organic compounds can be reversibly altered chemically to become more water-soluble.

This is a powerful technique and allows you to separate organic compounds from a mixture -- if they belong to different solubility classes.