Monoradical rearrangements of the 1,4-biradicals involved in Norrish type II photoreactions

1981 ◽  
Vol 103 (13) ◽  
pp. 3837-3841 ◽  
Author(s):  
Peter J. Wagner ◽  
Kou-Chang Liu ◽  
Y. Noguchi
Keyword(s):  
Type Ii ◽  
Norrish Type

Temperature Dependent Solvent Effects in Photochemistry of 1-Phenylpentan-1-ones

1999 ◽  
Vol 64 (12) ◽  
pp. 2007-2018 ◽  
Author(s):  
Petr Klán ◽  
Jaromír Literák
Keyword(s):  
Solvent Effects ◽  
Solvent Polarity ◽  
Structure Change ◽  
Type Ii ◽  
Temperature Dependent ◽  
Methyl Derivative ◽  
Methyl Substitution ◽  
Weak Bases ◽  
Norrish Type ◽  
Small Structure

Temperature dependent solvent effects have been investigated on the Norrish Type II reaction of 1-phenylpentan-1-one and its p-methyl derivative. Efficiencies of the photoreaction were studied in terms of solvent polarity and base addition as a function of temperature. Such a small structure change as the p-methyl substitution in 1-phenylpentan-1-one altered the temperature dependent photoreactivity in presence of weak bases. The experimental results suggest that the hydrogen bonding between the Type II biradical intermediate OH group and the solvent is weaker for 1-(4-methylphenyl)pentan-1-one than that for 1-phenylpentan-1-one at 20 °C but the interactions probably vanish in both cases at 80 °C.

ChemInform Abstract: Sequential Norrish Type II Photoelimination and Intramolecular Aldol Cyclization of 1,2-Diketones in Carbohydrate Systems: Stereoselective Synthesis of Cyclopentitols.

ChemInform ◽  
2009 ◽  
Vol 40 (9) ◽  
Author(s):  
Dimitri Alvarez-Dorta ◽  
Elisa I. Leon ◽  
Alan R. Kennedy ◽  
Concepcion Riesco-Fagundo ◽  
Ernesto Suarez
Keyword(s):  
Stereoselective Synthesis ◽  
Type Ii ◽  
Norrish Type ◽  
Aldol Cyclization
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