scholarly journals Stereoselective Synthesis of Highly-Congested Tetralin-Fused Spirooxindoles with Hydroxyl Group: Net Oxygen Atom Induced Hydride Shift/cyclization Process.

2021 ◽  
Author(s):  
Dan Sakai ◽  
mizuki machida ◽  
Keiji Mori
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Stereoselective Synthesis ◽  
Hydroxyl Group ◽  
Target Structure ◽  
Hydride Shift ◽  
Cyclization Process ◽  
Stereogenic Centers

Highly stereoselective synthesis of tetralin-fused spirooxindoles with two contiguous stereogenic centers. In the present reaction, not only [1,5]-hydride shift/cyclization process, but also replacemnt of nitrogen atom to oxygen atom ocurred smoothly to give target structure with hydroxy grop in good chemical yields with good to excellent diastereoselectivities (up to d.r. = >20:1). Investigation of the reaction mechanism suggested that this “atom-replacement” event ocurred via the iminium cation intermediates.

scholarly journals Stereoselective Synthesis of Highly-Congested Tetralin-Fused Spirooxindoles with Hydroxyl Group: Net Oxygen Atom Induced Hydride Shift/cyclization Process.

2021 ◽  
Author(s):  
Dan Sakai ◽  
mizuki machida ◽  
Keiji Mori
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Stereoselective Synthesis ◽  
Hydroxyl Group ◽  
Target Structure ◽  
Hydride Shift ◽  
Cyclization Process ◽  
Stereogenic Centers

Highly stereoselective synthesis of tetralin-fused spirooxindoles with two contiguous stereogenic centers. In the present reaction, not only [1,5]-hydride shift/cyclization process, but also replacemnt of nitrogen atom to oxygen atom ocurred smoothly to give target structure with hydroxy grop in good chemical yields with good to excellent diastereoselectivities (up to d.r. = >20:1). Investigation of the reaction mechanism suggested that this “atom-replacement” event ocurred via the iminium cation intermediates.

The constituents of Cryptocarya pleurosperma White & Francis. I. Pleurospermine: A new alkaloid of the leaves

1959 ◽  
Vol 12 (1) ◽  
pp. 90 ◽  
Author(s):  
E Gellert
Keyword(s):  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Hydroxyl Group ◽  
Veratric Acid ◽  
The Third ◽  
Tertiary Nitrogen Atom ◽  
Group A ◽  
Francis I ◽  
Alcoholic Hydroxyl ◽  
Tertiary Nitrogen

A new alkaloid pleurospermine, C14Hl9O3N, has been isolated from the leaves of Cryptocarya pleurosperma. Pleurospermine contains a methoxyl group, a phenolic hydroxyl group, and a tertiary nitrogen atom. The third oxygen atom is possibly present as an alcoholic hydroxyl group. On heating with palladium-charcoal the alkaloid yields 4-hydroxy-3-methoxyacetophenone (I), while methylation followed by oxidation gives veratric acid.

A stereoselective synthesis of sucrose. Part II. Theoretical and chemical considerations

1979 ◽  
Vol 57 (6) ◽  
pp. 645-652 ◽  
Author(s):  
Bert Fraser-Reid ◽  
David Erle Iley
Keyword(s):  
Melting Point ◽  
Stereoselective Synthesis ◽  
Primary Alcohol ◽  
Hydroxyl Group ◽  
Borohydride Reduction ◽  
Conjugated Diene

Under the agency of an iodonium ion, the tertiary anomeric hydroxyl of tetraacetyl fructofuranose adds stereoselectively in a 1,4 sense, to a pyranoid 4,6-O-benzylidenated conjugated diene receptor. The resulting disaccharide, isolated in 45% yield, is an hex-2-enopyranoside possessing an allylic primary iodide which can be oxidised to an aldehyde either directly or after hydrolysis to the allylic primary alcohol. The aldehyde is decarbonylated and the unsubstituted hex-2-enopyranoside formed undergoes hydroxylation giving exclusively the manno-diol. After protecting the equatorial hydroxyl as the benzoate ester, the axial 2-hydroxyl group is inverted via oxidation followed by borohydride reduction. Acetylation gives the known 4,6-O-benzylidene hexaacetyl derivative of sucrose, which is identified by mixture melting point.

scholarly journals Zum Mechanismus der Hydroxylierungen mit molekularem Sauerstoff und Zinn(II)-Komplexen

1969 ◽  
Vol 24 (5) ◽  
pp. 583-588 ◽  
Author(s):  
Volker Ullrich ◽  
Hansjürgen Staudinger
Keyword(s):  
Aqueous Solution ◽  
New Species ◽  
Oxygen Atom ◽  
Molecular Oxygen ◽  
Aromatic Compounds ◽  
Oxygen Molecule ◽  
Active Oxygen ◽  
Hydroxyl Group ◽  
Phosphate Complex ◽  
A New Species

Reduction of molecular oxygen by a stannous phosphate complex in aqueous solution leads to a new species of active oxygen capable of hydroxylating aliphatic and aromatic compounds. The hydroxylation reactions are shown to require two electrons per oxygen molecule reduced. The oxygen atom of the hydroxyl group is completely derived from molecular oxygen. This new mechanism has been proposed as a model for mixed function oxygenases.

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