13C magnetic resonance studies. 131. An examination of β-enolization in an unsaturated [3.2.1] system: 3,3-dimethylbicyclo[3.2.1]oct-6-en-2-one

1987 ◽  
Vol 65 (7) ◽  
pp. 1557-1562 ◽  
Author(s):  
Greg A. Antoniadis ◽  
Michael T. M. Clements ◽  
Sriyawathie Peiris ◽  
J. B. Stothers
Keyword(s):  
Electron Transfer ◽  
Magnetic Resonance ◽  
Conjugate Addition ◽  
Major Product ◽  
Single Electron ◽  
Reaction Pathways ◽  
Single Electron Transfer ◽  
Magnetic Resonance Studies ◽  
Efficient Reduction ◽  
Magnetic Resonance Spectra

Under homoenolization conditions (t-BuO−/t-BuOH/185 °C), 3,3-dimethylbicyclo[3.2.1]oct-6-en-2-one (5) is converted into six products through three reaction pathways. The major product, 3,3-dimethylbicyclo[3.3.0]octan-2-one, arises by unidirectional β-enolate rearrangement of 5 to the isomeric unsaturated [3.3.0] ketones, which (a) undergo efficient reduction to 2, by single electron transfer, and (b) suffer Haller–Bauer cleavage to two isomeric 2,2-dimethyl-3-cyclopentenylpropanoic acids. In competition with these processes is the reversible conjugate addition of t-BuO− to 5 to furnish the 6-tert-butoxy derivative, which undergoes β-enolate rearrangement to two isomeric ketones. The structures of these products were established primarily from their 1H and 13C magnetic resonance spectra.

13C magnetic resonance studies. 144. An examination of β-enolization in the bicyclo[3.3.1]- and [3.2.2]nonan-2-one system

1993 ◽  
Vol 71 (8) ◽  
pp. 1099-1105 ◽  
Author(s):  
David J. Muir ◽  
J.B. Stothers
Keyword(s):  
Electron Transfer ◽  
Magnetic Resonance ◽  
Major Product ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Magnetic Resonance Studies ◽  
Unsaturated Ketones ◽  
A Minor ◽  
Cis And Trans ◽  
Magnetic Resonance Spectra

While 3,3-dimethylbicyclo[3.3.1]nonan-2-one (5) is stable under strongly basic conditions (t-BuO−/t-BuOH/185 °C), its isomer, 3,3-dimethylbicyclo[3.2.2]nonan-2-one (6), is slowly transformed to 5. Similarly, 3,3-dimethylbicyclo-[3.2.2]non-6-en-2-one (8b) rearranges to a [3.3.1] isomer but the latter is not stable. Experiments with 3,3-dimethylbicyclo[3.3.1]non-6-en-2-one (7) revealed that it is converted to five compounds, none of which is 8b. The major product, 8,8-dimethylbicyclo[4.3.0]non-1(6),-en-7-one (11) arises from β-enolate rearrangement. Enone 11 undergoes slow reduction to cis- and trans-8,8-dimethylbicyclo[4.3.0]nonan-7-one, presumably by single electron transfer. Experiments with 11 alone showed that β-enolate rearrangement of 7 → 11 is unidirectional. Haller–Bauer cleavage to acidic products occurs as a minor process in the reactions of the unsaturated ketones. The structures of the products were established primarily from their 1H and 13C magnetic resonance spectra.

Reversal of Polarity by Catalytic SET Oxidation: Synthesis of Azabicyclo[m.n.o]alkanes via Chemoselective Reduction of Amidines

2021 ◽  
Author(s):  
Sundarababu Baskaran ◽  
Kirana D V ◽  
Kanak Kanti Das
Keyword(s):  
Electron Transfer ◽  
Stereoselective Synthesis ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Catalytic Method ◽  
One Pot ◽  
Oxidative System ◽  
Oxidation Synthesis

A one-pot catalytic method has been developed for the stereoselective synthesis of cyclopropane-fused cyclic amidines using CuBr2/K2S2O8 as an efficient single electron transfer (SET) oxidative system. The generality of this...

Evidence for single electron transfer in the reaction of alkoxides with alkyl halides

1984 ◽  
Vol 25 (45) ◽  
pp. 5107-5110 ◽  
Author(s):  
E.C. Ashby ◽  
Dong-Hak Bae ◽  
Won-Suh Park ◽  
Robert N. Depriest ◽  
Wei-Yang Su
Keyword(s):  
Electron Transfer ◽  
Alkyl Halides ◽  
Single Electron ◽  
Single Electron Transfer

The isolation, structure, and stereochemistry of traversiadiene. The precursor hydrocarbon of traversianal biosynthesis

1989 ◽  
Vol 67 (8) ◽  
pp. 1302-1304 ◽  
Author(s):  
Albert Stoessl ◽  
G. L. Rock ◽  
J. B. Stothers
Keyword(s):  
Magnetic Resonance ◽  
Biosynthetic Pathway ◽  
Nuclear Overhauser Effect ◽  
Difference Spectra ◽  
Heteronuclear Correlation ◽  
Magnetic Resonance Studies ◽  
Overhauser Effect ◽  
Effect Difference ◽  
Nuclear Overhauser ◽  
Magnetic Resonance Spectra

A tricyclic diene, traversiadiene, isolated from cultures of Cercosporatraversiana has been shown to have the structure and stereochemistry of the previously postulated hydrocarbon intermediate on the biosynthetic pathway to traversianal (1). Detailed:1H and 13C magnetic resonance studies, including homo- and heteronuclear correlation spectra, led to the gross structure, and the stereochemistry was established through a series of nuclear Overhauser effect difference spectra. Keywords: diterpene, traversiadiene, 1H and 13C magnetic resonance spectra.

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