Functional compound classes

The compounds involved and detected by analytical GC-MS workflows like volatiles, PCBs, or pesticides are discussed with representative mass spectra in the following sections. These compounds do not necessarily belong to the same functional compound class with a chemical classification for instance of amines, ester, phenols, hydrocarbons and others. Many standard references cover these characteristic fragmentation patterns of specific functional groups and compound classes in detail (Howe, 1981 McLafferty and Turecek, 1993 Budzikiewicz, 1998). 

Imines form the functional compound class of lowest rank and are hence named as such only when no N-organyl substituents are present otherwise they are named as. ..ylidenamines. If more senior functions are to be respected. ..imino prefixes are used. Totally systematic azane-based names would again bring about considerable simplifications. 

If such compounds actually contain the typical functional groups of organic chemistry, the customary ranking order of functional compound classes (see Table 7) within the limits of substitutive or conjunctive... 

Chapters 1,2, and 3 of this book have dealt in some detail with the nomenclature rules for parent structures and the wealth of different functional compound classes based there upon. The present chapter will recapitulate once again in a more summary manner the most important directives for the construction of the complete names of more complex compounds. This entails a reconsideration of the question of priorities for ring and chain systems already briefly approached in the pertinent sections of Chapter 1. Since functional groups must ultimately be included in the decisions, extension of the priority rules becomes imperative, as will be shown in the following sections. 

Extended series of trivial names that are to be retained (or just too frequently used to be simply omitted) have already been compiled in various tables of Chapter 1 of this book (fused polycycles Table l,p. 16, heterocycles Tables 2 and 3, p. 44,50). For the numerous trivial names to be dealt with in the domain of the functional compound classes of Chapter 2 it has been found more appropriate not to include them directly in the text but to confine them to a tabular appendix. Specific hydrocarbon systems such as terpenes and steroids, whose nomenclature is widely dominated by trivial names, are also accounted for in this appendix. 

Fig. 4. Distribution of compound classes in cmde oils as a function of boiling point. Region A represents normal paraffins B, isoparaffins C, naphthenes ...

All these 3,4-dihydro-2H-1 -benzopyran-2-ones 17 and 18 are substrates of class A and class C (3-lactamases. They are thus the first 8-lactones that are hydrolyzed by [3-lactamases. The kcat values for these substrates are generally smaller than those of the analogous acyclic phenaceturates suggesting that the tethered leaving group obstructs the attack of water on the acyl-enzyme. Despite the apparent advantage of the long-lived acyl-enzymes, the irreversible inhibition by the functionalized compounds is no better than that of acyclic molecules 16. Thus, even the tethered QM cannot efficiently trap a second nucleophile at the [3-lactamase active site, at least as placed as dictated by the structure of compounds 18.70... 

There are two distinct classes of compounds that fit the criteria mentioned above alkene-functionalized chalcone derivatives (Fig. IB) and enone-functionalized chalcone derivatives (Fig. 1C). Within each class, both aromatic and non-aromatic compounds exist. Those compounds functionalized at the alkene include i) 3-membered heterocycles, e.g., epoxide and aziri-dine compounds, ii) 5-membered aromatic derivatives including fused and non-fused compounds, and iii) 6-membered aromatic pyrazine compounds. The enone-functionalized compounds include i) 5-membered aromatics such as pyrazole and isoxazole compounds, ii) 5-membered non-aromatic compounds for example pyrazolines and isoxazolines, and iii) 6-membered non-aromatics where a discussion of heterocyclic and non-heterocyclic compounds will be given for completeness. 

Figure 2. General scheme of hydrocarbon formation as a function of burial of the source rock. The evolution of the hydrocarbon composition for three compound classes is shown schematically in the insets. Depths are only indicative and may vary according to the actual geological situation (from Engel and Macho, 1993).

Table 3.2 Some important compound classes and functional groups.

The majority of solutes will show decreased values of In k as the temperature is increased. The slopes of the van t Hoff plots are often similar for compounds of the same functional group as shown by the three solid lines. The dashed lines show the irregular results often seen for solutes of different compound classes which can vary widely and have either a positive or a negative slope. All of these systems can be easily modeled with optimization software and require only two temperature points to define the system [4],... 

The low thermal stability and the volatility of some of the low molecular weight stationary phases restricted their general use. Therefore, thermally stable and nonvolatile polymeric chiral stationary phases were developed by coupling the diamide phase, via the amino functionality, to a statistical copolymer of dimethylsiloxane and (2-carboxypropyl)methylsiloxane of appropriate viscosity131. The fluid polymeric phase, referred to as Chirasil-Val (Table 2), exhibits excellent properties for the enantiomer separation of a variety of compound classes over a broad temperature range141142. 

In an attempt to relate calculated results to experimental findings for monomeric, lignin model compounds, preliminary work has compared theoretically determined electron densities and chemical shifts reported from carbon-13 nuclear magnetic resonance spectroscopy (62). Although chemical shifts are a function of numerous factors, of which electron density is only one, both theoretical and empirical relationships of this nature have been explored for a variety of compound classes, and are reviewed by Ebra-heem and Webb (63), Martin et al. (64), Nelson and Williams (65), and Farnum (66). 

This chapter discusses the transition metal catalyzed functionalization of such systems that fall outside the topic of Chapters 6 and 7, as well as certain other compound classes (e.g. purines, pyrones). In contrast to the abundant literature of the chemistry of five and six membered systems, the transition metal catalyzed transformations of other heterocycles have not been studied so far in the same depth, probably due to the limited availability of their halogen derivatives compared to haloazines and haloazoles. Purine compounds and their structural analogues constitute an exception, since their biological importance proved to be a strong drive for synthetic chemist worldwide.1... 

Compound (Class), Functional Group Of, (H-Donor) A (H-Acceptor)... 

Figure 5.2 Aqueous solubility of the (subcooled) liquid compound at 25°C as a function of the estimated molar volume (Vjx, see Box 5.1) of the molecule for various compound classes. The linear regression equations and correlation coefficients (R2) for the various sets of compounds are given in Table 5.4. Note that for practical reasons, decadic instead of natural logarithms are used.

Figure 5.8 Ratio of the activity coefficient in water (y/w) and in methanol/water [20% (v v) and 40% (v v) methanol] as a function of the molar volume (Vix, see Box 5.1) of the solute log(y // ) = a Vix + b. The three compound classes include the following compounds ...

Note that for compound classes such as phenols, anilines, and pyridines where the acid (base) function is in resonance with the aromatic ring, the p values obtained are significantly greater than 1 (Table 8.6) that is, the electronic effect of the substituents is greater than in the case of benzoic acid. 

Francko, D. A., and R. T. Heath. 1979. Functionally distinct classes of complex phosphorus compounds in lake water. Limnology and Oceanography 24 453 173. 

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