Cinnamic alcohol, formerly also designated styrone, is found in volatile oils, not as such, but as ester. As acetate it occurs in cassia oil; as cinnamate (styracin) in storax, also in the oils of hyacinth (?), xanthorrhoea resin, Peru balsam and Honduras balsam.
It is commonly obtained by saponification of the styracin in storax. Synthetically it can be obtained by reduction of cinnamic aldehyde diacetate and subsequent saponification of the resulting cinnamyl acetate.2)
Cinnamic alcohol occurs in long, fine white needles which possess a hyacinth-like odor. At 33° they melt to a colorless, strongly refractive liquid, which boils at 257,5° (758 mm.), respectively at 117° (5 mm.) At 35o/15o its specific gravity lies between 1,01 and 1,03. In water it is sparingly soluble (about 1 :250), also in petroleum ether. In the other solvents it is readily soluble. Of 30 p. c. alcohol about 50 to 60 vols., of 50 p. c. alcohol 4 to 5 vols, and of 60 p. c. alcohol about 2 vols, are needed to effect solution.
With platinum black, cinnamic alcohol is oxidized to cinnamic aldehyde, upon more violent oxidation to cinnamic acid (m. p. 133°) and finally to benzaldehyde and benzoic acid. Upon reduction with sodium amalgam in the presence of much water it can be converted into phenylpropyl alcohol.
1) Walbaum, Berl. Berichte 33 (1900), 2300, footnote. 2) Barbier and Leser, Bull. Soc. chim. III. 33 (1905), 858.
Characteristic derivatives are the phenylurethane melting at 90 to 91,5° and the diphenylurethane melting at 97 to 98V) The latter is to be preferred to the phenylurethane since it has the more sharply marked melting point.