Benzoic acid and benzyl alcohol are the most used raw materials in cosmetics and pharmaceutical industries as preservative ingredients. Cinnamon cassia oil is an important natural starting material to synthesize organic compounds because it contains a high amount of cinnamaldehyde and benzaldehyde. Thanks to green chemistry techniques using mild solvents such as water and ethanol, as well as low-cost and safe reagents such as potassium permanganate, and sodium borohydride, this natural starting material was used to synthesize high yields of benzoic acid, benzyl alcohol, cinnamyl alcohol, phenylpropanol, and cinnamic acid; these products are used in cosmetics, pharmaceutical, and food industries. Various reaction conditions were applied to find convenient green chemistry procedures. Equivalents (molar) of catalysts to starting materials were optimized. The highest yields (60–90%) were achieved using water as a solvent, potassium permanganate as an oxidation catalyst, and sodium borohydride as a reduction catalyst. Water was used as a solvent in all reactions except phenylpropanol. The uses of a single natural starting material, water as a solvent, and mild reagents to synthesize five important organic compounds are all in line with green chemistry techniques.