Deuterium labeling, and

Deuterium-labeling and mass spectrometry prove that the mechanism of the thermal O to N rearrangement of 4-alkoxypyridines to N-alkyl-4-pyridones is intermolecular (88CS347). 

Thompson, D. C. Perera, K. London, R. Studies on the mechanism of hepatotoxicity of 4-methylphenol(/j-cresol)—effects of deuterium labeling and ring substitution. Chem.-Biol. Interact. 1996, 101, 1-11. 

Depending on the nature of the substituents X1, X2, and X3, the reactions produced nitrones (148) (as indole derivatives) or annelated isoxazolines (149). The authors performed a series of experiments (including one with the use of a deuterium label) and suggested a mechanistic scheme for the interpretation... 

Fragmentation of the nitroethylene radical cation has been studied by deuterium labelling and tandem mass spectrometry and compared to the fragmentation of the corresponding nitrosoethylene61. 

Direct irradiation of orf/io-divinylbenzene (164) leads to the formation of the benzobi-cyclo[3.1.0]hex-2-ene isomer 167 as the major product. Deuterium labelling and methanol trapping experiments suggested the intermediacy of both 165 and 166, the expected products of irradiation of a benzannelated 1,3,5-hexatriene (equation 62)144. 

A case where the absolute configuration was unambiguously assigned using a combination of stereoselective deuterium labeling and NMR analysis is discussed. 

Alkanediazonium ions may lose a proton to give a diazoalkane when loss of nitrogen to form a carbonium ion is unfavorable. Product formation by way of diazoalkanes can be detected by deuterium labelling, and has been shown to be most likely for primary alkanedia-... 

K. Kakinuma, Y. Iihama, I. Takagi, K. Ozawa, N. Yamauchi, N. Imamura, Y. Esumi, and M. Uramoto, Diacetone glucose architecture as a chirality template. II. Versatile synthon for the chiral deuterium labelling and synthesis of all diastereomers of chirally monodeuterated glycerol, Tetrahedron 48 3163 (1992). 

Extensive deuterium labelling and measurements of metastable ion transitions aided elucidation of the fragmentation pathways for tetrahydropyran <68OMS(l)403). These are presented in Scheme 4. 

The (/ -complexes all undergo thermal rearrangement to /2, /4-bicyclo[4.2.1]nona-2,4,7-triene tricarbonyl complexes. The possible mechanism of the rearrangement of the molybdenum complex has been thoroughly investigated by deuterium labeling and kinetic studies228. 

R Liardon, S Ledermann, U Ott. Determination of D-amino acids by deuterium labelling and selected ion monitoring. J Chromatogr 203 385-395, 1981. 

The stereospecific deuterium labeling and subsequent photo-oxidation of the olefin 5 and similar olefins 6 and 7 revealed the hidden regioselectivity of the... 

Based on the results of deuterium labelling and radical trapping experiments with dicyclohexylphosphine (DCHP), it was proposed that the reaction occurs by the S l mechanism. A major difference, however, is an additional propagation step involving iodine atom abstraction from 42b by the radical intermediate 49, to give the substitution product 46 and radical intermediate 50, that continues the chain propagation cycle of the S l mechanism (equation 51). 

The ketone (22) has been studied in detail by deuterium labelling and it was shown that transfer of hydrogen (H-3 and H-4) occurred in approximately equal amounts (107) Green and Djerassi, 1967). The... 

Amelung, W., and Brodowski, S. (2002). In vitro quantification of hydrolysis-induced racemization of amino acid enantiomers in environmental samples using deuterium labeling and electron-impact ionization mass spectrometry. Anal. Client. 74, 3239-3246. 

Evidence for this mechanism is (i) 2 equivalents of RLi are required (2) the hydrogen in the product comes from the water and not from the adjacent carbon, as shown by deuterium labeling and (2) the intermediates 32-34 have been trapped. This reaction, when performed in tetramethylenediamine, can be a synthetically useful method of generating vinylic lithium compounds (34), which... 

In crude enrichment cultures fermenting formate, C02 sometimes does not incorporate to a major extent into the methane (24). It remains to be confirmed with the use of deuterium labeling and hypophosphite inhibition, whether direct formate reduction can occur significantly in pure cultures. 

Exploration of the mechanism of coenzyme reduction by model reactions using deuterium labelling and structural variation. Both these reactions were carried out in aqueous (D2O in the first case) buffer solutions without enzyme. 

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