Robert L. Crecelius

Bio: Robert L. Crecelius is an academic researcher. The author has contributed to research in topics: Claisen rearrangement & Carroll rearrangement. The author has an hindex of 1, co-authored 3 publications receiving 6 citations.

The Claisen and Cope Rearrangements

Abstract: Since the first observation of a thermal rearrangement vinyl allyl ether to the corresponding homoallylcyclic carbonyl compound by Claisen in 1912, rearrangements of vinyl and aryl allylic ethers have been extensively studied and exploited for their synthetic value. The corresponding rearrangement of substituted 1,5-hexadiene was first recognized by Cope in 1940 as the carbon analog of the Claisen rearrangement. Today it is recognized that such transformations fall within the general category of a [3,3] sigamtropic reaction and that considerable variation may be accommodated in the basic requirement of a system of six atoms with terminal unsaturated linkage. This chapter attempts to survey the vas t accumulation of Claisen and Cope rearrangements recorded since the first coverage in 1944. Keywords: Claisen rearrangments; Cope rearrangements; allyl ethers; aliphatic rearrangements; anomalies; amine rearrangements; thio rearrangements; migration; experimental procedures

Chapter 4 The Unimolecular Decomposition and Isomerization of Oxygenated Organic Compounds (other than Aldehydes and Ketones)

Abstract: Publisher Summary This chapter discusses substituent effects, linear free energy relations, kinetic isotope studies, and conformation analysis of products. Existing interpretations of such data have been summarized, and in some instances, new interpretations have also been presented. It discusses relative rate and kinetic isotope studies, which are conceded reliable, and to contribute significantly to the elucidation of the kinetics. Photochemical and irradiation induced reactions do not produce unimolecular reactions, which can be studied quantitatively; therefore, the vast majority of the reactions reviewed here are those induced thermally. To facilitate the presentation of the data, organic group class, for example, alcohols, anhydrides, ethers, esters, acids, and peroxides have grouped reactions, and have all been reviewed in detail. This provides a convenient data reference source, but has the distinct disadvantage of not emphasizing the similarities in mechanism, which exist among molecules of the various organic group classes. It examines that kinetic results for gas phase and for solution and other condensed phases are presented separately.

Zur Kinetik der Claisen‐Umlagerung. Zur Kenntnis der Claisen‐Umlagerung VIII

Abstract: Es wurde die thermische Umlagerung des radioaktiven (2,6-Di-methyl-4-allylphenyl)-allylathers und des 2,4-Dimethylphenyl-allylathers kinetisch analysiert und die daraus ermittelten Reaktionsgrossen mit denjenigen anderer Claisen-Umlagerungen verglichen.

Oxidative Phosphorylation: Synthesis of Adenosine Diphosphate by the Oxidation of Quinol Phosphates

Abstract: THE importance of oxidative phosphorylation in the respiratory chain of living organisms has led to intensive research into the possible in vivo and in vitro mechanisms of phosphorylation1, and several theories have been advanced which postulate quinol phosphates2–4 (or analogous nitrogenous systems derived from riboflavin5,6) as the active intermediates in phosphate transfer.

The Many Chemists Who Could Have Proposed the Woodward‐Hoffmann Rules But Didn't: The Organic Chemists Who Knew of the Smoking Guns **

Abstract: It is a reasonable question to ask, why, as of 1965 when the five Woodward‐Hoffmann communications appeared, did no other organic chemist discover the orbital symmetry rules for pericyclic reactions? The previous two papers in this 27‐paper series on the history of the Woodward‐Hoffmann rules discussed the physical chemists, chemical physicists, and theoretical chemists who could have solved the pericyclic no‐mechanism problem; and the organic chemists in whose laboratory many of the key hints to this problem were found but still did not solve the problem. The stories of 16 other chemists who knew of (at least portions of) the pericyclic no‐mechanism problem are presented in this paper. Social, political, and scientific explanations are presented as partial rationalizations as to why none of these individuals – except Woodward with Hoffmann – solved the pericyclic no‐mechanism problem.