Fragrants

C5H10O2, CHjCOOPr. Colourless liquid with a fragrant odour b.p. 88 C. Manufactured by leading propene into hot ethanoic acid containing sulphuric acid, or by heating isopropyl alcohol with ethanoic and sulphuric acids. Used as a solvent for cellulose nitrate and various gums. 

The napthanes (C H2n), or cycloalkanes, are ring or cyclic saturated structures, such as cyclo-hexane (CgH 2) though rings of other sizes are also possible. An important series of cyclic structures is the arenes (or aromatics, so called because of their commonly fragrant odours), which contain carbon-carbon double bonds and are based on the benzene molecule. 

Alkenes are hydrocarbons that contain a carbon-carbon double bond A carbon-carbon double bond is both an important structural unit and an important func tional group m organic chemistry The shape of an organic molecule is influenced by the presence of this bond and the double bond is the site of most of the chemical reactions that alkenes undergo Some representative alkenes include isobutylene (an industrial chemical) a pmene (a fragrant liquid obtained from pine trees) md fame sene (a naturally occurring alkene with three double bonds)... 

Benzoic acid had been known for several hundred years by the time of Mitscher lich s experiment Many trees exude resinous materials called balsams when cuts are made m their bark Some of these balsams are very fragrant which once made them highly prized articles of commerce especially when the trees that produced them could be found only m exotic faraway lands Gum benzoin is a balsam obtained from a tree that grows m Java and Sumatra Benzoin is a word derived from the Erench equivalent benjoin which in turn comes from the Arabic luban jawi meaning incense from Java Benzoic acid is itself odorless but can easily be isolated from gum benzoin... 

Many esters occur naturally Those of low molecular weight are fairly volatile and many have pleasing odors Esters often form a significant fraction of the fragrant oil of fruits and flowers The aroma of oranges for example contains 30 different esters along with 10 carboxylic acids 34 alcohols 34 aldehydes and ketones and 36 hydrocarbons... 

Essential is also used as the adjective form of the noun essence The mixtures of substances that make up the fragrant material of plants are called essential oils because they contain the essence that is the odor of the plant The study of the composition of essential oils ranks as one of the oldest areas of organic chemical research Very often the principal volatile component of an essential oil belongs to a class of chemical sub stances called the terpenes... 

The lonones are fragrant substances present in the scent of ms and are used in perfume A mixture of a and 3 lonone can be prepared by treatment of pseudoionone with sulfuric acid... 

In contrast, aromatic ketones are high boiling, colorless Hquids that generally have a fragrant odor and are almost insoluble in water. They are useful as intermediates in chemical manufacture. Functionalized and cycHc ketones are also good solvents. Ring size and the type and location of functional groups affect odor, color, and reactivity of these ketones. 

The use of fragrant substances has been continuous, and the use of Hpids or emoUients for anointing is fully documented in historical writings. However, it is probably not justifiable to identify the recipes passed on from antiquity as cosmetics. The compositions based on folklore and mysticism were replaced by more scientifically acceptable products beginning about 1875. The first edition of a handbook of cosmetic chemistry pubHshed in 1920 included a foreword noting that scientific cosmetic chemistry did not exist prior to that pubHcation (1). A few years later, texts on cosmetic chemistry and other formularies became available (2). 

A fragrant substance found in cucumber and melon produces the NMR spectra set 38. The identity and structure of the substance can be derived from these spectra without any further information. Conditions CDCI3, 30 mg per 0.3 ml, 25 °C, 400 MHz ( //), 100 MHz ( C). 

In 1786 William Nieholson wrote A Dictionary of Practical and Theoretical Chemistry. In this work Nicholson mentions that a chemist named Neuman, on distillation of storax (a balsam derived from the tree Liquambar orientalis), had produced a fragrant empyreumatic oil . In 1839 E. Simon carried out some similar experiments, apparently quite independently, and again obtained this essential oil which he ealled styrol. In 1845 M. Glenard and R. Boudault reported on the production of styrol (now known as styrene) by dry distillation of dragons blood, a resin obtained from the fruit of the Malayan rattan palm. 

Observable Characteristics - Physical State (as normally shipped) Liquid Color Colorless Odor. Sharp, fragrant. 

Chemical Designations - Synonyms Methacrylate monomer Methacrylic acid, methyl ester Methyl alpha-methylacrylate Methyl 2-methyl-2-propenoate Chemical Formula CHj=C(CH3)COOCHj Observable Characteristics - Physical State (as shipped) Liquid Color Colorless Odor Sharp, fragrant pleasant smelling pungent ester. 

Other interesting synthetic applications of the ketone-derived enamine alkylation are found in the monomethylation of steroid enamines (249), extension of the benzylation reaction (250) to a ferrocene derivative (251), the use of a-bromoesters (252) and ketones (252) or their vinylogues (25J), in the syntheses of alantolactone (254-256), isoalantolactone (257), and with a bridged bis-enamine (258). The use of bifunctional alkylating agents is also seen in the introduction of an acetylenic substituent in the synthesis of the characteristic fragrant constituent of jasmine (259), the synthesis of macrocyclic ketolactones (260), the use of butyrolactone (261), and the intermolecular or intramolecular double alkylations of enamines with dihalides (262). 

Spermaceti and cetyl palmitate have been widely used in the making of cosmetics, fragrant soaps, and candles. 

Chemistry of fragrant compounds (lactones and other 0-heterocycles) 98T7633. 

Heterocycles in industrial synthesis of fragrant and flavoring substaces in Czech Republic 99CLY412. 

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