Group double bonds

Functional group Double bond Triple bond... 

If there is no functional group, double bond, or triple bond, then we should number the chain so that the substituent has the lower number ... 

The carbonyl carbon can accept this electron pair because one pair of electrons of the carbon-oxygen group double bond can shift out to the oxygen. 

The synthesis of lipidated peptides is implicated by the base-lability of the thioester and the acid sensitivity of the prenyl group double bonds. Thus, new protecting groups are required which can be removed under extremely mild, preferably neutral, conditions. 

In order to determine the reactivity ratios, the relation between monomer feed and copolymers composition was examined. However, in this case the calculation of reactivity ratios is more complex than simple copolymerization of two vinyl monomers. The question arises - how can we calculate the molar ratio of comonomers Should we use a mole concentration of hoth comonomers, or, for multimethacrylate concentration, should we apply a mole concentration of reactive groups (double bonds) Both methods are used and discussed in the literature. The results of reactivity ratio computations are presented in Table 5.2... 

The conclusions which one draws in consideration of the above facts are that both the physical and chemical properties of hydrocarbon molecules are largely a function of the electron distribution. The structural elements which play a prominent role in this distribution are chain length, chain branching, methyl groups, double bonds, and benzene nuclei. 

NMR chemical shifts give us information about the proximity of electronegative atoms (e.g., oxygen) and unsaturated groups (double bonds and aromatic rings). In this discussion we will ignore the protons attached directly to oxygen (OH) because they provide little... 

Betaines, with 1,2-vinylene linking group double bond rotation barriers, 60, 226 formation, 60, 205, 2( -9. 213-4. 216 nmr spectra. 60, 224-6, 227 theoretical calculations, 60, 240-1 Bicyclo(2.2.0]hexa-2,5-dienes, see Dewar benzenes... 

An area of recent intense synthetic endeavor has been in the syntiiesis of the avermectins and milbe-mycins, which contain a range of highly reactive functionalities such as the spiroacetal group, double bonds, and epimerizable centers. However, dimethyl sulfoxide activated oxidations, most notably the Swem variation, have teen useful in this area of chemistry. For example, the sensitive spiroacetal (34) gave 92% of the derived aldehyde using dimetiiyl sulfoxide-oxalyl chloride-triethylamine at -SO C (equation 15). ... 

Similar to substituent contributions to retention, the contributions of other structural features can be determined. Such contributions to HPLC retention were examined [71] for steroids with cholesterol as the parent structure. The features considered were the presence and absence of methyl and ethyl groups, double bonds and hydroxyl groups in the nucleus and side chain, the chirality at C3 and C24, the configuration about certain double bonds, and the length of the side chain and its branching. 

Zeolites do not only catalyze isomerizations of pure hydrocarbons. Also for molecules bearing a polar functional group, double bond and skeletal rearrangements can be performed without conversion of the functional group. Suitable zeolites should be rather apolar with a low concentration of acid sites, e.g., HZSM5. The interaction of polar functional groups with the pore walls of these rather apolar zeolites are weak [57]and hence polarization and... 

Cytokinin specificity is determined by the structure of its side chain, where even a small modification can significantly affects the biological activity. Among enzymatic modifications that have been already proved in vivo are ranked O-glycosylation and O-acetylation of zeatin, cisJtrans isomerization of its hydroxyl group, double bond reduction to dihydrozeatin and hydroxylation of A -isopentenyl moiety of isopentenyladenine type to zeatin-types of cytokinins. 

Because of low cost, the most widely used unsaturated polyester polymer is in the form of 60% to 80% solutions of the prepolymer in copolymerizable monomers such as styrene and a mix of styrene with methyl methacrylate. During hardening, the polyester prepolymer and the monomer react through their unsaturated groups (double bonds). 

Hydrogenation. The iron complex 1 is a highly selective hydrogenation catalyst for reducing the carbonyl group. Double bond, triple bond, halogen atoms, cyclopropane and pyridine rings are not affected. 

Reduction of azides to amines. The reduction of azides to amines is usually carried out by catalytic hydrogenation or with lithium aluminum hydride. Neither method is selective. Corey et al. have used Lindlar catalyst for selective reduction of azides in the presence of carbonyl groups, double bonds, and benzyl ether groups. An acetylenic function is also reduced to the cti-olefin. Representative amines obtained in this way, with the yields, are formulated. 

The aryllithiums derived from iV,iV-diallylarylamines with an ortho halogen by exchange with an alkyllithium cyclise by addition to an allyl group double bond generating a primary alkyllithium which can be trapped with electrophiles finally producing indolines. ... 

Ultraviolet (UV) and visible (VIS) spectra of lipids result from electronic excitations and transitions in the Upid molecule. Hence, functionalities with high electron density (e.g., carboxyl groups, double bonds) absorb strongly in the UV or VIS spectrum with characteristic maximum wavelengths (X nj ) and extinction coefficients (8max). Values for common UV-absorbing functionalities are shown in Table 3.9. 

On the other hand, when the 2-norbornyl cation is formed from its A -cyclopentenyl-ethyl precursor ( it-route ), the more flexible structure of the precursor makes it possible for the participating group (double bond) to move closer to the reaction centre which results in a decreasing a-effect for the exo isomer. 

Isopropyl 2-iodoxybenzoate is a useful reagent for the clean, selective oxidation of organic sulfides to sulfoxides [1127]. This reaction proceeds without overoxidation to sulfones and is compatible with the presence of the hydroxy group, double bond, phenol ether, benzylic carbon and various substituted phenyl rings in the molecule of organic sulfide. Duschek and Kirsch have reported that isopropyl 2-iodoxybenzoate in the presence of trifiuoroacetic anhydride can be used for the a-hydroxylation of p-keto esters at room temperature in THF [1128]. 

Lipids present an excellent opportunity for the production of bioplastics. They can be directly polymerized using free-radical or cationic processes with the addition of some additives. The reactivity present in many triglycerides (hydroxyl groups, double bonds) allows for the facile manipulation to whatever the desired functional group for polymerization may be. Triglycerides are an excellent, sustainable platform chemical for polymer production the explosion in their use since the early 2000s will only continue as concerns over petrochemical feedstocks and prices grow. 

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