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Clar's rule states that for a benzenoid polycyclic aromatic hydrocarbon (i.e. one with only hexagonal rings), the resonance structure with the largest number of disjoint aromatic π-sextets is the most important to characterize its chemical and physical properties.
According to Clar's rule, [20] the resonance structure of a PAH that has the largest number of disjoint aromatic pi sextets—i.e. benzene-like moieties—is the most important for the characterization of the properties of that PAH. [21] Benzene-substructure resonance analysis for Clar's rule
Erich Clar (23 August 1902 – 27 March 1987) was an Austrian organic chemist, born in Hřensko, who studied polycyclic aromatic hydrocarbon chemistry. He is considered as the father of that field. [ 1 ]
Based on Woodward–Hoffmann rules, the electrocyclic opening of norcaradiene derivatives is a 6-electron disrotatory (π 4 s + σ 2 s), thermally allowed process. ring opening. The norcaradiene-cycloheptatriene equilibrium has been studied extensively. [18] The position of the equilibrium depends upon steric, electronic and conformational ...
Also, there are no carbocation rearrangements, as the acylium ion is stabilized by a resonance structure in which the positive charge is on the oxygen. The viability of the Friedel–Crafts acylation depends on the stability of the acyl chloride reagent. Formyl chloride, for example, is too unstable to be isolated.
The hydroxy acid first reacts with the 2,2'-Dipyridyldisulfide to form the corresponding 2-pyridinethiol ester, and after a proton transfer, the alkoxide attacks the carbonyl carbon, forming a tetrahedral transition state, before resolving back to the desired lactone and 2-pyridinethione.
When I began investing, I was starting from a knowledge base of zero. One of the first books I read was The Motley Fool's Rule Breakers, Rule Makers. In it, Motley Fool co-founder Tom Gardner laid ...
The Leimgruber–Batcho indole synthesis is a series of organic reactions that produce indoles from o-nitrotoluenes 1. The first step is the formation of an enamine 2 using N,N-dimethylformamide dimethyl acetal and pyrrolidine.