C30Hs~02-A Solid Alcohol from Flower Petals Since 1806 when Sertiirner first obtained morphine from the opium poppy, an immense number and variety of organic compounds have been isolated from plant sources and their structures elucidated. Very little of this storehouse of chemical knowledge has found its way into laboratory manuals, even though the procedures and equipment required for certain botanically oriented chemical experiments are within reach of the facilities of almost any college laboratory. A relatively simple natural product experiment can be carried out on the petals of the white prickly poppy, genus A~gemone,whose representatives are found in a t least 30 of the 50 states, primarily in the southern two thirds of the nation.' These plants bloom between late March and May, depending on the temperature, elevation, rainfall, and soil conditions. A typical plant with blossoms, A. ourontiaea Ownb., is shown in the figure. The experiment starts with petal picking, a n activity requiring caution and gloves because of the numerous sharp spines on the leaves and stalk of most species of Argemone. Since the petals contain water to the extent of 85% by weight, about 150-200 g of fresh material is required; it is dried in air or, more quickly, with a rotary evaporator. IJurmg the drying operation the petals tend to darken but this change in color does not appear to lower the yield of the desired product. The dried petals are weighed and extracted overnight with ligroin or cyclohexane in a Soxhlet extractor. Upon cooling, the yellow extraction solution will deposit a grayish precipitate more of which can be recovered by evaporating t h e solution nearly to dryness and rinsing away the carotenes with cold solvent. The yield of crude product is of the order of 1% of dry petal weight. Upon recrystallization from 95% ethanol the chalky gray powder yields a whitish solid having a melting point of 115-116°C and an infrared spectrum characteristic of a long chain alcohol. When heated with sulfur, the solid produces hydrogen sulfide gas, a reaction typical of secondary alcohols.2 An ester can be readily prepared by heating the white solid with acetic anhydride on a steam bath for several hours and then pouring the reaction mixture over cracked ice. The acetate appears as a wooly white substance having a relatively low melting point of 34-38°C. The solubility of the ester in the usual organic solvents is considerably greater than that of the parent alcohol. The fact that the alcohol, actually a glycol, is a solid a t all comes as a surprise to many students who have the notion that all alcohols are liquids. Although the exact structure of the alcohol, 10,ll-triacontanediol ( C J ~ H ~ ~was O ~determined I, only recently," this newness of knowledge lends an air of relevancy to the experiment and illustrates how science proceeds from the firm footing of the well-established into the area of the unknown. A further pedagogical value is offered to the student by concretely demonstrating that not all chemicals are found in bottles. I thank Brother Simon Scribner, C.S.C. for supplying the photograph. Ownbey, G. B., Memoirs of the Torrey Botanical Club, 21.7 (1958). Feigl, Fritz, "Spot Tests in Organic Analysis," 6th Ed., Elsevier Publishing Company, New York, 1960, p. 187. a Dorninguez, X. A., and Barragan, V., J. Org. Chem., 30,2049 (1965). a
Thomas McCullough, C.S.C. St. Edward's University Austin, Texas 78704
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Journal of Chemical Education
