Fragrance structure

Donnoli MI, Scafato P, Nardiello M, Casarini D, Giorgio E, Rosini C. Enantioselective synthesis and absolute stereochemistry of both the enantiomers of trans-magnolione, a fragrance structurally related to trans-methyl jasmonate. Tetrahedron 2004 60(23) 4975-4981. 

C03-0106. The following molecules are known for their characteristic fragrances. For each one, convert the line structure into a complete structural formula and calculate its molar mass. 

Plants produce a vast array of terpenes, alkenes built in multiples of five carbon atoms. Many terpenes have characteristic fragrances. For example, the fresh odor of a pine forest is due to pinene, a ten-carbon molecule with a ring structure and one double bond. The fragrances of terpenes make them important in the flavor and fragrance industry. Limonene, another ten-carbon molecule with a ring and two double bonds, is the principal component of lemon oil. Geraniol, a chainlike molecule with two double bonds, is one of the molecules that is responsible for the fragrance of roses and is used in many perfumes. Many other terpenes have important medicinal properties. 

Various terpene-derived materials are important in the formulation of fragrances and flavors. One example is the tricyclic furan shown below, which is commercially used under the trademark Ambrox. The synthetic sequences below have been developed to prepare related structures. Suggest reagents for each step in these sequences. 

Besides their essential roles in nature, isoprenoids are of commercial importance in industry. Some isoprenoids have been used as flavors, fragrances, spices, and food additives, while many are used as pharmaceuticals to treat an array of human diseases, such as cancer (Taxol), malaria (artemisinin), and HIV (coumarins). In contrast to the huge market demand, isoprenoids are present only in low abundance in their host organisms. Thus, isolation of the required isoprenoids consumes a large quantity of natural resources. Furthermore, owing to their structural complexity, total chemical synthesis is often not commercially feasible. For these reasons, metabolic engineering may provide an alternative to produce these valuable isoprenoids [88,89]. 

Chudy coal grade (Poland), 6 713t Chum salmon, common and scientific names, 3 187t Chundles, 24 58 Chymosin, 10 251, 296, 309 12 65 recovery of recombinant, 3 845—846 Chypre fragrances/perfumes, 13 358, 361 Cialis, molecular formula and structure, 5 182t... 

The bees must have some important role for these chemicals, for without them their lives are shorter. They possess remarkable structures for collecting and storing scents and devote enormous effort to the task. Why do they do this What do they do with the chemicals they collect Unfortunately, we know too little about euglossine bees to answer these questions definitively. It is easy to attract and trap male bees using synthetic fragrance chemicals such as cineole as bait, but females are considerably more difficult to find. As a result, several euglossine species are known only through male specimens, and much in these creatures lives remains hidden from our view. 

Organic chemistry is the study of compounds that are based on carbon. Natural gas, rubbing alcohol, aspirin, and the compounds that give fragrance to a rose, are all organic compounds. In this chapter, you will learn how to identify and name molecules from the basic families of organic compounds. You will be introduced to the shape, structure, and properties of different types of organic compounds. 

We can do more. We can make a simple structural change to this ester and obtain a new fragrance. If we replace the methyl group by an ethyl group, to get ethyl butyrate and the smell of pineapple ... 

Beets MGJ, Odor and stimulant structure, in Theimer ET (ed.). Fragrance Chemistry, The Science of the Sense of Smell, Academic Press, New York, USA, pp. 77-122, 1982. 

Figure 5 suggests that nitrated and nitro-free musks have common structural features that can be used to differentiate them from nonmusks. We consider this to be a significant result. Fragrance chemists have long sought to find the overlap between nitrated and nitro-free musks in terms of the structural features that a compound must possess in order to evoke a musk odor. Further-... 

The number of synthetically produced fragrance and flavor chemicals has since expanded continually as a result of the systematic investigation of essential oils and fragrance complexes for odoriferous compounds. Initially, only major components were isolated from natural products their structure was then elucidated and processes were developed for their isolation or synthesis. With the development of modern analytical techniques, however, it became possible to isolate and identify... 

Similarity between odors arises because dissimilar substances or mixtures of compounds may interact with receptors to create similar sensory impressions in the sensory centers of the brain. The group of musk fragrances (comprising macro-cyclic ketones and esters as well as aromatic nitro compounds and polycyclic aromatics) are, for example, compounds with similar odors but totally different structures [5, 6]. Small changes in structure (e.g., the introduction of one or more double bonds in aliphatic alcohols or aldehydes) may, however, alter a sensory... 

Fragrances must be volatile to be perceived. Therefore, in addition to the nature of the functional groups and the molecular structure of a compound, the molecular mass is also an important factor. Molecular masses of ca. 200 occur relatively frequently masses over 300 are an exception. 

Fragrance and flavor materials of commercial interest are arranged according to the Beilstein system of functional groups, not according to their sensory properties, since relationships between odor and structure are difficult to establish. However, the Beilstein system has been abandoned in a few cases for practical reasons. 

The acyclic terpenes are discussed separately in Section 2.2. Some of the cycloaliphatic fragrance and flavor materials are structurally related to the cyclic terpenes and are, therefore, discussed in Section 2.4 after the cyclic terpenes. 

Acyclic terpene (Cjo) and sesquiterpene (C15) hydrocarbons find little use in flavor and fragrance compositions. They are relatively unstable and some have a slightly aggressive odor due to their highly unsaturated structure. 

Although having very similar structures, the different isomers show very different sensory properties and lead to very different effects when used in fragrance and flavour compositions. 

In addition to cyclic terpenoids, several other cycloaliphatic compounds have above-average importance as fragrance materials some of them are structurally related to the terpenes. 

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