Photochemistry of alpha-keto phosphate esters Photorelease of a caged cAMP

We report our results on a phosphate photoprotecting (or cage) group that rapidly releases phosphate (kr>10 8 s -1 ) in nearly quantitative yield by efficient photolysis of the caged phosphate. As a demonstration of this strategy, cAMP was generated with an efficiency of 34% and a first-order rate constant of 3x10 8 s -1 by irradiation of benzoin cAMP, a caged nucleotide.