Efficient One-Step Synthesis of Bis-Spiroketals from Diynediols by π-Lewis Acid-Catalyzed Hydroalkoxylation/Hydration

2011 ◽  
Vol 6 (8) ◽  
pp. 1961-1966 ◽  
Author(s):  
Ivan Volchkov ◽  
Kamlesh Sharma ◽  
Eun Jin Cho ◽  
Daesung Lee
Keyword(s):  
Lewis Acid ◽  
One Step ◽  
Acid Catalyzed

A One-step Regioselective Construction of the Steroid Skeleton by Lewis Acid Catalyzed High Pressure Diels-Alder Reaction1

1993 ◽  
Vol 2 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Easter Gacs-baitz ◽  
Lucio Minuti ◽  
Hans W. Scheeren ◽  
Roberta Selvaggi ◽  
Aldo Taticchi
Keyword(s):  
High Pressure ◽  
Lewis Acid ◽  
Diels Alder ◽  
One Step ◽  
Acid Catalyzed ◽  
Steroid Skeleton

Highly efficient Lewis acid catalyzed, one step conversions of 16α,17α-epoxy-3β-hydroxypregn-5-en-20-one to d-homosteroid and Δ13-steroids

Tetrahedron ◽  
2001 ◽  
Vol 57 (33) ◽  
pp. 7199-7204 ◽  
Author(s):  
Navdeep K Girdhar ◽  
M.P.S Ishar ◽  
Rajiv Kumar ◽  
Rajinder Singh ◽  
Gurmit Singh
Keyword(s):  
Lewis Acid ◽  
Highly Efficient ◽  
One Step ◽  
Acid Catalyzed

scholarly journals Unveiling the Lewis Acid Catalyzed Diels–Alder Reactions Through the Molecular Electron Density Theory

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2535 ◽  
Author(s):  
Luis R. Domingo ◽  
Mar Ríos-Gutiérrez ◽  
Patricia Pérez
Keyword(s):  
Electron Density ◽  
Lewis Acid ◽  
Diels Alder ◽  
Strong Electron ◽  
High Acceleration ◽  
Molecular Electron ◽  
One Step ◽  
Molecular Electron Density Theory ◽  
Acid Catalyzed ◽  
Zwitterionic Intermediate

The effects of metal-based Lewis acid (LA) catalysts on the reaction rate and regioselectivity in polar Diels–Alder (P-DA) reactions has been analyzed within the molecular electron density theory (MEDT). A clear linear correlation between the reduction of the activation energies and the increase of the polar character of the reactions measured by analysis of the global electron density transfer at the corresponding transition state structures (TS) is found, a behavior easily predictable by analysis of the electrophilicity ω and nucleophilicity N indices of the reagents. The presence of a strong electron-releasing group in the diene changes the mechanism of these P-DA reactions from a two-stage one-step to a two-step one via formation of a zwitterionic intermediate. However, this change in the reaction mechanism does not have any chemical relevance. This MEDT study makes it possible to establish that the more favorable nucleophilic/electrophilic interactions taking place at the TSs of LA catalyzed P-DA reactions are responsible for the high acceleration and complete regioselectivity experimentally observed.

ChemInform Abstract: Highly Efficient Lewis Acid Catalyzed, One-Step Conversions of 16α,17α-Epoxy-3β-hydroxypregn-5-en-20-one to D-Homosteroid and Δ13-Steroids.

ChemInform ◽  
2010 ◽  
Vol 32 (50) ◽  
pp. no-no
Author(s):  
Navdeep K. Girdhar ◽  
M. P. S. Ishar ◽  
Rajiv Kumar ◽  
Rajinder Singh ◽  
Gurmit Singh
Keyword(s):  
Lewis Acid ◽  
Highly Efficient ◽  
One Step ◽  
Acid Catalyzed
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