Lecture Organic chemistry - Chapter 15: Benzene and Informatics. In this chapter, we will explore the structural implications of the stabilizing effects of aromaticity. The discussion will introduce the key ideas by focussing on the unique properties of benzene, the prototypical aromatic molecule. One new chemical reaction appears, electrophilic aromatic substitution, of benzene (using a variety of reagents, leading to different products). This reaction is elaborated in the next chapter, where the substrate is a substituted benzene. | 1825: Faraday discovers benzene by pyrolysis of whale oil: Colorless liquid bp ~80°C. Very unreactive. Analysis: : C H : 1 1 Benzene and Aromaticity Cyclic structure: Kekulé 1865 Michael Faraday 1791-1867 Resonance: 9/14/2014 © University of California 1 Benzoin resin or styrax resin is a balsamic resin obtained from the bark of several species of trees in the genus Styrax. It is used in perfumes, some kinds of incense, as a flavoring, and medicine (see tincture of benzoin). Its principal component is benzoic acid.[1][2] Commonly called "benzoin", it is called "benzoin resin" here to distinguish it from the crystalline compound benzoin. Benzoin resin does not contain this crystalline compound. Benzoin is also called gum benzoin or gum benjamin, but "gum" is incorrect as benzoin is not a water-soluble polysaccharide. Its name came via the Italian from the Arabic lubān jāwī (لبان جاوي, "frankincense from Java"), because it was brought from Indonesia. The Catalan traders, who bought . | 1825: Faraday discovers benzene by pyrolysis of whale oil: Colorless liquid bp ~80°C. Very unreactive. Analysis: : C H : 1 1 Benzene and Aromaticity Cyclic structure: Kekulé 1865 Michael Faraday 1791-1867 Resonance: 9/14/2014 © University of California 1 Benzoin resin or styrax resin is a balsamic resin obtained from the bark of several species of trees in the genus Styrax. It is used in perfumes, some kinds of incense, as a flavoring, and medicine (see tincture of benzoin). Its principal component is benzoic acid.[1][2] Commonly called "benzoin", it is called "benzoin resin" here to distinguish it from the crystalline compound benzoin. Benzoin resin does not contain this crystalline compound. Benzoin is also called gum benzoin or gum benjamin, but "gum" is incorrect as benzoin is not a water-soluble polysaccharide. Its name came via the Italian from the Arabic lubān jāwī (لبان جاوي, "frankincense from Java"), because it was brought from Indonesia. The Catalan traders, who bought lubān jāwī from moorish traders, modified the word by changing a to e and omitting the lu to benjawi. Italians further changed it into benjuì, and in Latin it became ultimately known as benzoë. Nomenclature Substituted benzenes: alkylbenzene, halobenzene, nitrobenzene, etc. (Functional groups have priority). Disubstituted: ortho meta para Functional groups take over: General term for benzene derivatives: Arene. C6H5- is phenyl; general aryl. C6H5CH2- is phenylmethyl or benzyl. IUPAC accepted 9/14/2014 © University of California 3 Acetophenone is a crystalline ketone that is used as a solvent for cellulose ethers and esters in the manufacture of alcohol-soluble resins. These in turn are used in perfume. Acetophenone is used to create fragrances that resemble almond, cherry, honeysuckle, jasmine, and strawberry. It is used in chewing gum. It can be found naturally in apple, cheese, apricot, banana, beef and cauliflower. This chemical may be obtained by the dry distillation of a mixture of .
