13C magnetic resonance studies. 138. An examination of the [3.2.2.0] → [4.2.1.0] rearrangement via β-enolization and H/D exchange in tricyclic ketones

1989 ◽  
Vol 67 (2) ◽  
pp. 187-192
Author(s):  
Sriyawathie Peiris ◽  
J. B. Stothers ◽  
Shirley E. Thomas
Keyword(s):  
Magnetic Resonance ◽  
Butyl Alcohol ◽  
Rearrangement Product ◽  
Methylene Carbon ◽  
Deuterium Incorporation ◽  
Magnetic Resonance Studies ◽  
Endo Isomer ◽  
Tert Butyl ◽  
Tert Butyl Alcohol

The behavior of the endo and exo isomers of 7,7-dimethyltricyclo[3.2.2.02,4]nonan-6-one (9, 17) under strongly basic conditions (t-BuO−/t-BuOH/185 °C) has been examined. In both cases rearrangement to the corresponding 8,8-dimethyl-tricyclo[4.2.1.02,4]nonan-7-one (11, 18) was found, with the exo isomer reacting approximately 8 times faster. Experiments in tert-butyl alcohol-O-d1 were carried out to determine the specific sites, the relative rates, and the stereochemistry of deuterium incorporation in the initial ketones. Although H/D exchange occurs most readily at the cyclopropyl methylene carbon in the endo isomer, none of the rearrangement product expected to arise via γ-enolate formation was observed. The results for these ketones are compared with our earlier observations in the related [2.2.2], [3.2.1.0], and [3.3.1.0] systems. Keywords: homoenolization, tricyclic ketones, H/D exchange.

13C nuclear magnetic resonance studies. 114. An examination of the [3.3.1.0] → [4.3.0.0] rearrangement via β-enolization and H/D exchange in tricyclic ketones

1985 ◽  
Vol 63 (6) ◽  
pp. 1250-1257 ◽  
Author(s):  
Arthur J. Ragauskas ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ring Expansion ◽  
Butyl Alcohol ◽  
Deuterium Incorporation ◽  
Magnetic Resonance Studies ◽  
Endo Isomer ◽  
Exchange Processes ◽  
Tert Butyl Alcohol ◽  
13C Nuclear Magnetic Resonance

The behavior of the exo and endo isomers of 7,7-dimethyltricyclo[3.3.1.02,4]nonan-6-one (5, 6) under strongly basic conditions (t-BuOH/t-BuOH/185 °C) has been examined. In sharp contrast to their [3.2.1.02,4] analogs, the endo isomer is stable while the exo readily rearranges to 8,8-dimethyltricyclo-[4.3.0.02,4]nonan-7-one (16). Experiments were carried out in tert-butyl alcohol-O-d1 to establish the sites of deuterium incorporation in the initial ketones as well as the relative rates and stereoselectivities of the exchange processes. Ketones 5 and 6 were prepared through ring expansion by ketonization of cyclopropoxides generated from the [3.2.1.0] homologs; the stereochemistry of these ketonizations was established by 2H labelling.

ChemInform Abstract: CARBON-13 NUCLEAR MAGNETIC RESONANCE RELAXATION IN HYDROGEN BONDED TERT-BUTYL ALCOHOL AND PHENOL

1975 ◽  
Vol 6 (29) ◽  
pp. no-no
Author(s):  
EDWIN E. TUCKER ◽  
THOMAS R. CLEM ◽  
JEFFREY I. SEEMAN ◽  
EDWIN D. BECKER
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Butyl Alcohol ◽  
Nuclear Magnetic Resonance Relaxation ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Resonance Relaxation ◽  
Nuclear Magnetic ◽  
Hydrogen Bonded

Nuclear magnetic resonance studies. XL. Tricyclooctanone rearrangement, [3.2.1.0] → [3.3.0.0], via γ-enolization and a 2Hmr study of H/D exchange in tricyclic ketones

1984 ◽  
Vol 62 (7) ◽  
pp. 1385-1391 ◽  
Author(s):  
A. K. Cheng ◽  
Ashim K. Ghosh ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Membered Ring ◽  
Deuterium Incorporation ◽  
Magnetic Resonance Studies ◽  
Endo Isomer ◽  
Exchange Processes ◽  
Initial Transformation ◽  
Nuclear Magnetic

The effect of strongly basic conditions (t-BuO−/t-BuOH/185 °C) on the exo and endo isomers of 7,7-dimethyltri-cyclo[3.2.1.02.4]octan-6-one has been examined. While the exo isomer is stable, the endo isomer readily rearranges to 4,4-dimethyltricyclo[3.3.0.02.8]octan-3-one (6) which subsequently undergoes reduction of the three-membered ring. The initial transformation is one of very few examples of γ-enolate rearrangement. Experiments in tert-buiyl alcohol-O-d1 were carried out to establish the several sites of deuterium incorporation in the initial ketones and in 6 using 2Hmr. These results reveal the stereochemistry of γ-enolate formation and cleavage as well as the stereoselectivities and relative rates of the exchange processes.

Homoenolization and H/D exchange in tricyclic ketones. Rearrangement via a γ-enolate

1981 ◽  
Vol 59 (24) ◽  
pp. 3379-3381 ◽  
Author(s):  
A. K. Cheng ◽  
A. K. Ghosh ◽  
I. (Tse) Sheepy ◽  
J. B. Stothers
Keyword(s):  
Electron Transfer ◽  
Butyl Alcohol ◽  
Membered Ring ◽  
Deuterium Incorporation ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Shed Light

Under homoenolization conditions (t-BuO−, t-BuOH, 185 °C), 7,7-dimethyltricyclo[3.2.1.02,4]octan-6-one (5) readily rearranges to 4,4-dimethyltricyclo[3.3.0.02,8]octan-3-one (6) which subsequently suffers reduction of the three-membered ring, presumably by electron transfer from the tert-butoxide anion for which some evidence has been obtained. The conversion of 5 to 6 constitutes one of very few examples of rearrangement via a γ-enolate. From reactions in tert-butyl alcohol-O-d1, deuterium incorporation at the several sites in 5 and 6 undergoing H/D exchange was directly monitored by 2Hmr spectroscopy; these results shed light on the stereochemistry of homoenolate formation and cleavage.

Carbon-13 nuclear magnetic resonance relaxation in hydrogen bonded tert-butyl alcohol and phenol

1975 ◽  
Vol 79 (10) ◽  
pp. 1005-1008 ◽  
Author(s):  
Edwin E. Tucker ◽  
Thomas R. Clem ◽  
Jeffrey I. Seeman ◽  
Edwin D. Becker
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Butyl Alcohol ◽  
Nuclear Magnetic Resonance Relaxation ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Resonance Relaxation ◽  
Nuclear Magnetic ◽  
Hydrogen Bonded

Thermodynamic and Kinetic Investigation of the Solvent Effect on the Oxidation of [Co(en)2SCH2COO]+ with S2O82- In Water-Methanol and Water-tert-Butyl Alcohol Mixtures

1993 ◽  
Vol 58 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko
Keyword(s):  
Transfer Functions ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Oxidation Of Co ◽  
Kinetics Of Oxidation ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Alcohol Mixtures ◽  
Kinetics Of

The kinetics of oxidation of [Co(en)2SCH2COO]+ with S2O82- was studied in water-methanol and water-tert-butyl alcohol mixtures. Changes in the reaction activation parameters ∆H≠ and ∆S≠ with varying concentration of the co-solvent depend on the kind of the latter, which points to a significant role of salvation effects. The solvation effect on the reaction is discussed based on a comparison of the transfer functions ∆Ht0, ∆St0 and ∆Gt0 for the initial and transition states with the changes in the activation parameters accompanying changes in the CO-solvent concentration. The transfer enthalpies of the reactant were obtained from calorimetric measurements.

scholarly journals Impacts of Sn(II) doping on the Keggin heteropolyacid-catalyzed etherification of glycerol with tert-butyl alcohol

2021 ◽  
pp. 116913
Author(s):  
Márcio José da Silva ◽  
Diego Morais Chaves ◽  
Sukarno Olavo ferreira ◽  
Rene Chagas da Silva ◽  
Jose Balena Gabriel Filho ◽  
...  
Keyword(s):  
Butyl Alcohol ◽  
Tert Butyl ◽  
Tert Butyl Alcohol
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