They react to form water-soluble soaps when reacted with alkali, ammonia, amines, and form oil soluble soaps when reacted with the salts of heavy metals. Although many of the reactions of Rosin acids are the same as those of fatts acids, a few others should be mentioned. The reaction with lime or zinc oxide produce a high melting oil that is used in varnishes and printing inks. There is interest in a small fraction of the beta-sitosterol. It has been used to synthesize sex hormones and other compounds such as cortical steroids or cortisone.
Terpenes are organic solvents that are derived from citrus or pine oil.
Terpenes generally have a strong odor, even at low concentrations thus they are easy to recognize. Terpenes are not very reactive towards metals and most polymers lead to their use as industrial cleaners. Many are used to clean off heavy petroleum based greases as well as being used to clean printed circuit boards. A good overview of wood chemical derivatives can be found in Union Camp's chemical products page.