Photochemical cleavage and release of carboxylic acids from alpha-keto amides.
Carboxylate groups incorporated at the position alpha to the keto carbonyl of alpha-keto amides 1 were photochemically cleaved in aqueous media to give carboxylic acids in 70-90% yields with quantum yields of 0.3. The cleavage coproducts were diastereomeric hemiacetals 2. Prompt release of acetate and gamma-aminobutyrate (GABA) in buffer was observed by difference FT-IR spectroscopy upon 355 nm laser flash photolysis. The time-constant for release of GABA was <30 ms. [reaction--see text]
Ma
Chicheng
C
Department of Chemistry, Marquette University, Milwaukee, WI 53201-1881, USA.
Steinmetz
Mark G
MG
Cheng
Qing
Q
Jayaraman
Vasanthi
V
D000085:Acetates / Q000737:chemistry; D000577:Amides / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry; D015394:Molecular Structure; D010782:Photolysis; D017550:Spectroscopy, Fourier Transform Infrared; D005680:gamma-Aminobutyric Acid / Q000737:chemistry
D000085:Acetates; D000577:Amides; D002264:Carboxylic Acids; D007659:Ketones; D005680:gamma-Aminobutyric Acid