The Thermal Decomposition of Allyltrimethyl-Ammonium Hydroxide

Howton, David R.

doi:10.1021/jo01153a001

Cited by 9 publications

(1 citation statement)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, it was recently recognized that such reactions may be more complex. Thus in the electrophilic addition of hydrogen bromide to allene, it was found that considerable quantities of 1,3-dibromo-l,3-dimethylcyclobutane [two isomers, (20) and (21)] were formed as well as products of the type (18) and (19) [651.…”

Section: Elect R O P H I I Ic a D D I T I O N Smentioning

confidence: 99%

Progress in the Chemistry of Allene

Griesbaum¹

1966

Angew. Chem. Int. Ed. Engl.

View full text Add to dashboard Cite

oxylase reaction (carboxydismurase). The object was to find whether the C02 is attached to C-2 or C-4 of the ri bulose diphosphate (4) before cleavage into two molecules of 3-phosphoglyceric acid (5). An intramolecularly doubly labeled [2-14C-2-D]phosphoglyceric acid (5a) can be formed as well as the unlabeled acid only if the C02 is attached to C-2. Since the [14C]glycolic acid obtained from the phosphoglyceric acid exhibited an isotope effect of 2.5 on oxidation with glycolic acid oxidase, this glycolic acid must have contained D as well as 14C. i.e. the CO;? is attached to C-2 in (4). 3-Tritiated (4) reacts four to six times more slowly than the H compound in the carboxylation at pH 8.1 and 25 "C. The release of the proton appears to be the limiting step of the overall reaction 11151.In the irreversible formation of a C-H bond by proton abstraction from a solvent in which the hydrogen is partially labeled, a much smaller content of the higher hydrogen isotopes is usually found in the product than in the solvent. This is a result of the isotope effect in the cleavage of an X-H bond. where X may be 0, S, N, etc. A typical example, which has been studied both experimentally and theoretically, is the hydration of isobutylene in acidic media 11211. When this reaction is carried out in I-I20/D20 mixtures, the concentration of D in the t-butyl alcohol formed is 3.9 times lower than that in the water; the ratio for T is 7.1, and that for T in D20 is 1.9.Corresponding biochemical examples are : In the enzymatic cleavage of citrate in HOT, T is incorporated into acetyl CoA. Hydrogen is incorporated preferentially, in the ratio kH/kT = 6.7 [1221. In the cleavage of threo-D,-isocitrate to succinate and glyoxylate, an isotope effect of kH/kT = 6.5 to 13.9 is found, depending on the isocitrate concentration (2x 10-3 to 4x 10-3 M), when the reaction is carried out in a buffer solution containing tritium [1231. In the cleavage of phosphoenol pyruvate by pyruvate kinase in HOT, T is incorporated with an isotope effect kH/kT of 6.4 [Iz4]. b) I s o t o p e E f f e c t s of C a r b o nLynn and Yunkwich[971studied the isotope effect of the urease reaction (with urea having the natural 12C/13C ratio) as a function of conversion, concentration, buffer, temperature, pH, and aging of the enzyme, and found a maximum value of 2.3%. The differences of the isotope effects found for various enzyme preparations were in some cases larger than the differences found for the above variables. The isotope effect of 5 to 10% found by other authors could not be confirmed.A 14C isotope effect of an unusual magnitude was found [119] for the enzymatic oxidation of [14C]formate by formic acid dehydrogenase. The value of 1.27 at 37 "C was independent of the substrate activity, which varied between 0.8 and 100 pCi/mmole. The decarboxylation of oxalacetate to pyruvate by an enzyme from Micrococcus lysodeikticus shows no isotope effect with the I3C-labeled substrate. The Mn(n)-catalysed, non-enzymatic decarboxylation, on the other hand, gives an isotope e...

show abstract

Section: Elect R O P H I I Ic a D D I T I O N Smentioning

confidence: 99%

Progress in the Chemistry of Allene

Griesbaum¹

1966

Angew. Chem. Int. Ed. Engl.

View full text Add to dashboard Cite

show abstract

Olefins from Amines: TheHofmann Elimination Reaction and Amine Oxide Pyrolysis

Cope

Trumbull

2011

Organic Reactions

View full text Add to dashboard Cite

The conversion of an amine to an olefin by elimination of the nitrogen atom and an adjoining hydrogen atom is a useful procedure for degradation and synthesis. The Hofmann exhaustive methylation method has been used most often to bring about change, but other methods as the thermal decomposition of amine oxides and the pyrolysis of amine phosphates or acetyl or benzoyl derivative have often been employed to advantage. This chapter reviews the Hofmann elimination because of its extensive history. Alternative methods are considered.

show abstract

Preparation of Acetylenes

1971

Compendium of Organic Synthetic Methods

View full text Add to dashboard Cite

The Thermal Decomposition of Allyltrimethyl-Ammonium Hydroxide

Cited by 9 publications

References 12 publications

Progress in the Chemistry of Allene

Progress in the Chemistry of Allene

Olefins from Amines: TheHofmann Elimination Reaction and Amine Oxide Pyrolysis

Preparation of Acetylenes

Contact Info

Product

Resources

About