2,5-Dimethylphenacyl carbonates: a photoremovable protecting group for alcohols and phenols.
Synthesis and photochemistry of a photochemically removable protecting group for alcohols and phenols, based on the 2,5-dimethylphenacyl (DMP) chromophore, is described. DMP carbonates release the corresponding hydroxy group containing molecules in high isolated yields (>70%), with quantum yields Phi= 0.1-0.2 in methanol and Phi= 0.36-0.51 in cyclohexane. The reactions proceed predominantly by the triplet pathway via E-photoenols, the lifetimes of which of approximately 2 s or 3 ms in cyclohexane or methanol, respectively, were determined by laser flash photolysis.
Literak
Jaromír
J
Department of Organic Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, CZ-611 37 Brno, Czech Republic.
Wirz
Jakob
J
Klán
Petr
P
D000438:Alcohols / Q000737:chemistry*; D001555:Benzene Derivatives / Q000138:chemical synthesis / Q000737:chemistry*; D002254:Carbonates / Q000138:chemical synthesis / Q000737:chemistry*; D007834:Lasers; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry*; D010777:Photochemistry; D010782:Photolysis; D011789:Quantum Theory; D014466:Ultraviolet Rays
D000438:Alcohols; D001555:Benzene Derivatives; D002254:Carbonates; D010636:Phenols