Carbon atoms primary, secondary, tertiary

Previously, it was mentioned that the steric characteristics of the carbon atom (primary, secondary, tertiary) should be considered it becomes clear with the new classes of compounds studied that the electronic characteristic of the substituent groups—aryl, hydroxyl, alkoxyl— must also be taken into account. Thus, whereas trisalkylperoxy radicals have weak recombination constants, dialkylhydroxy or dialkylalkoxy have much higher recombination constants, occasionally similar to values observed for secondary alkyl radicals. 

Classification of alcohols. Alcohols are classified according to the type of carbon atom (primary, secondary, or tertiary) bonded to the hydroxyl group. Phenols have a hydroxyl group bonded to a carbon atom in a benzene ring. 

It consists in treating a solution of sodium iodide in pure acetone with the organic compound. The reaction is probably of the S 2 type involving a bimolecular attack of the iodide ion upon the carbon atom carrying the chlorine or bromine the order of reactivities of halides is primary > secondary > tertiary and Br > Cl. 

The terms primary- secondary, tertiary, and quaternary are routinely used in organic chemistry, and their meanings need to become second nature. For example, it we were to say, "Citric acid is a tertiary alcohol," we would mean that it has an alcohol functional group (-OH) bonded to a carbon atom that is itself bonded to three other carbons. (These other carbons may in turn connect to other functional groups). 

Identify the carbon atoms in the following molecules as primary, secondary, tertiary, or quaternary ... 

In most paraffins there will be different numbers of hydrogens attached to the carbon atoms. There are four types of carbon atoms with names corresponding to the number of bonds made with other carbon atoms or functional groups. These names are primary, secondary, tertiary, and quaternary, as shown above. In a compound such as isopentane, there are three primary carbon atoms, one secondary, and one tertiary. 

The database of Garbon Atom Gontribuhons contains increments for different types of carbons that are not involved in any funchonal group. They differ by their state of hybridization (sp, sp sp ), number of attached hydrogens or branching (primary, secondary, tertiary and quaternary), cyclization (cyclic and noncyclic) and aromaticity (nonaromahc, aromatic and fused aromatic). 

In the structures obtained from the simulations ca. 61.7 % of the carbon atoms belong to the main chain and c.a. 36.5 % to the primary branches, i.e. less than 2% appears in the branches of higher order. The lengths of the longest observed primary, secondary, tertiary branches are 28, 11, and 7, respectively. However, the average lengths of those branches are muchshorter 1.6, 2.3, and 0.3. Only one quaternary methyl branch was obtained in all the simulations. 

Data for the specific rate coefficients for abstraction from CH bonds have been derived from experiments with hydrocarbons with different distributions of primary, secondary, and tertiary CH bonds. A primary CH bond is one on a carbon that is only connected to one other carbon, that is, the end carbon in a chain or a branch of a chain of carbon atoms. A secondary CH bond is one on a carbon atom connected to two others, and a tertiary CH bond is on a carbon atom that is... 

Primary, secondary, tertiary, and quarternary carbon atoms are symbolized by 1°, 2°, 3°, and 4 , respectively. Using this notation, the connectivity symbol 3° (2°) in Table 4.3 indicates the observed carbon k to be tertiary and attached to a secondary carbon l. 

Fig. 5.1 demonstrates for cholestane-3-one the utility of recording proton broadband-decoupled spectra, performing. /-modulated spin echo experiments, and generating subspectra from linear combinations of DEPT experiments for the unequivocal identification of primary, secondary, tertiary and quaternary carbon atoms. 

Formation of the new bond can involve two primary carbon atoms, or a primary and a secondary carbon atom, or two secondary carbon atoms, or even tertiary carbon atoms. 

DMD is suitable for the oxidation of most substrates with substances that are resistant to oxidation, however, the more reactive but also more expensive methyl (trifluoromethyl)dioxirane (TFD) is necessary. The oxidation is stereoselective for both dioxiranes and proceeds with complete retention of configuration at the oxidized carbon atom (Scheme 1) [20-22]. The reactivity follows the usual order of electrophilic oxidation-primary < secondary < tertiary < benzylic < allylic C-H bonds. Except for tertiary C-H bonds, which produce the oxidatively inert tertiary alcohols, further oxidation of the primary product (an alcohol) to a ketone or aldehyde (the latter is readily further oxidized to the corresponding acid) is possible, because the a-hydrogen of the alcohol is usually more reactive than that of the unactivated alkane, especially for allylic C-H bonds. 

One way of organizing the alcohol family is to classify each alcohol according to the type of carbinol carbon atom the one bonded to the —OH group. If this carbon atom is primary (bonded to one other carbon atom), the compound is a primary alcohol. A secondary alcohol has the —OH group attached to a secondary carbon atom, and a tertiary alcohol has it bonded to a tertiary carbon. When we studied alkyl halides (Chapter 6), we saw that primary, secondary, and tertiary halides react differently. The same is hue for alcohols. We need to learn how these classes of alcohols are similar and under what conditions they react differently. Figure 10-2 shows examples of primary, secondary, and tertiary alcohols. 

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