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On a benzene ring, the Hammett equation classifies a methoxy substituent at the para position as an electron-donating group, but as an electron-withdrawing group if at the meta position. At the ortho position, steric effects are likely to cause a significant alteration in the Hammett equation prediction which otherwise follows the same trend as ...
Another example is the bicyclic OBO protecting group (4-methyl-2,6,7-trioxa-bicyclo[2.2.2]octan-1-yl) which is formed by the action of (3-methyloxetan-3-yl)methanol on activated carboxylic acids in the presence of Lewis acids. The group is base stable and can be cleaved in two steps under mild conditions, mildly acidic hydrolysis yields the ...
For example, NaC 6 H 5 CO 2, the sodium salt of benzoic acid (C 6 H 5 COOH), is called sodium benzoate. Where an acid has both a systematic and a common name (like CH 3 COOH, for example, which is known as both acetic acid and as ethanoic acid), its salts can be named from either parent name.
Substituent Name (in approximate order of deactivating strength) Structure Type of electronic effect Directing effect Strong trifluoromethylsulfonyl group [13]-SO 2 CF 3 –I, –M meta (substituted) ammonium groups [14]-NR 3 + (R = alkyl or H) –I nitro group-NO 2 –I, –M sulfonic acids and sulfonyl groups-SO 3 H, -SO 2 R cyano group-C≡N
Combining the names of functional groups with the names of the parent alkanes generates what is termed a systematic nomenclature for naming organic compounds. In traditional nomenclature, the first carbon atom after the carbon that attaches to the functional group is called the alpha carbon ; the second, beta carbon, the third, gamma carbon, etc.
Omeprazole and elemicin are examples of useful molecules containing phenol ether substituents. Phenol ethers are often utilized in pharmaceutical design as a substituent that acts as a hydrogen-bond acceptor but not a hydrogen-bond donor; this allows many oral medications to follow Lipinski’s rule of five. [8]
Currently, there is no definitive explanation for the ortho effect, but it is hypothesized that there may be intramolecular assistance from the meta-directing group influencing the positioning of the incoming substituent. [3] For example, the electrophilic aromatic nitration of 1-methyl-3-nitrobenzene affords 4-methyl-1,2-dinitrobenzene and 1 ...
The more general method omits only the terminal "e" of the substituent name, but requires explicit numbering of each yl prefix, even at position 1 (except for -ylidyne, which as a triple bond must terminate the substituent carbon chain). Pentan-1-yl is an example of a name by this method, and is synonymous with pentyl from the previous guideline.