Organic chemistry tautomerization reaction

Cambridge University Press, 1954) 146. On Ingold s move to UCL, J. W. Baker was appointed "Reader in the Mechanism of Organic Reactions" and F. Challenger was appointed "Professor of Organic Chemistry" at Leeds. Baker s book is Tautomerism (London Routledge, 1934), with an appendix by Ingold. 

The details of the organic chemistry of the reaction of ethylene with PdCl2 (equation (1) above) are also known and are shown in Fig. 9.2. The palladium ion complexes with ethylene and water molecules and the water adds across the bond while still complexed to palladium. The palladium then serves as a hydrogen acceptor while the double bond reforms. Keto-enol tautomerism takes place, followed by release of an acetaldehyde molecule from the palladium. 

REARRANGEMENT (Organic Chemistry). These are reactions involving the transfer of an atom or group from one part of the molecule to another. Tautomcrism is a special case of rearrangements in which the two forms are in dynamic equilibrium. See Tautomerism in entry on Isomerism. When such reactions take place, the establishment of structural formulas becomes complex. Some of the better known rearrangements include ... 

Deamination of amino acids by carbonyl compounds has long been known in organic chemistry. Classical instances are the Strecker reaction of amino acids with alloxan and rimilar reactions with o-quinones, isatin, ninhydrin, methylglyoxal, and the like. In such cases deamination is usually associated with decarboxylation of the amino acid. Condensation of the amino and carbonyl groups to yield SchiiTs bases, and tautomeric transformation of these, are generally assumed as intermediary steps. 

Lowry is best known to chemistry students through the tradition of eponymony, since the proton theory of acidity is known as the "Bronsted/Lowry theory" of proton donors. His most important experimental investigation likely was a long series of studies on optical rotatory dispersion.49 For our purposes, there is special interest in his discovery of mutarotation in camphor derivatives and his theory of dynamic tautomerism, which led him to an ionic theory of organic reaction mechanisms. 

Short-lived organic radicals, electron spin resonance studies of, 5, 53 Small-ring hydrocarbons, gas-phase pyrolysis of, 4, 147 Solid state, tautomerism in the, 32, 129 Solid-state chemistry, topochemical phenomena in, 15, 63 Solids, organic, electrical conduction in, 16, 159 Solutions, reactions in, entropies of activation and mechanisms, 1, 1 Solvation and protonation in strong aqueous acids, 13, 83 Solvent effects, reaction coordinates, and reorganization energies on nucleophilic substitution reactions in aqueous solution, 38, 161 Solvent, protic and dipolar aprotic, rates of bimolecular substitution-reactions in,... 

This chapter describes the chemistry of carbanionic species having a carbonyl function at the -posi-tion, relative newcomers among synthetically useful carbanionic species. The chemistry of homoenolates is complicated by the problem of tautomerism between oxyanionic and carbanionic isomers through a process that formally involves homoconjugation. The synthetic problem caused by this tautomerism is much more severe in homoenolate chemistry (Scheme 1) than in enolate chemistry (Scheme 2), which also has a similar problem, since the carbanionic tautomer (1 Scheme 1) once formed often undergoes rapid and irreversible cyclization to the oxyanionic tautomer (2), and rarely acts as a carbon nucleophile. Until recently, therefore, chemists have not been able to make use of carbanionic homoenolates for organic syntheses. " However, a large number of useful homoenolate reactions have recently been discovered, and are described in this chapter. 

---