Non-aromatic compounds

Reactions of Non-aromatic Compounds 4.04.2.2.1 Isomers of aromatic derivatives... 

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. 

Most gel-permeation applications have been with hydrophilic gel particles in aqueous systems, although gels have been prepared and used with organic solvents [24,25]. The gels have some weak adsorption and ion-exchange characteristics and possess the ability to retain aromatic molecules longer than non-aromatic compounds of similar molecular weight. 

Non-aromatic chiral compounds are also resolved on the polysaccharide-based CSPs. Several non-aromatic compounds resolved on cellulose tribenzoate (OB) are shown in Figure 15.83 The detection by a UV detector is often difficult and an RI detector is more useful to detect the enantiomer peaks. 

Returning to the statistics for dipole moment in Table 6.8, the group of 265 compounds containing oxygen (but no other heteroatom except halogen) shows the lowest correlations between the semiempirical methods and B3LYP (AMI R2 = 0.776, PM3 R2 = 0.701, PM5 R2 = 0.726) except for PM5 with a still slightly lower R2 value for the 42 compounds with phosphorus or sulfur atoms or both (0.716). Moreover, with both AMI and PM3 the 276 non-aromatic compounds yield lower correlation coefficients than the 331 aromatic compounds (AMI 0.763 vs. 0.859, PM3 0.731 vs. 0.801). 

If you work through this book from beginning to end your impression may be that aromatic compounds can be synthesized in many ways, but that one always starts from aromatic compounds. This is the case. Nonetheless, it may occasionally be advantageous to obtain an aromatic from a non-aromatic compound. This is demonstrated in Figure 12.12 using a synthesis of mesitylene (B) from acetone as an example. The mechanism comprises many individual... 

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