Premium
THE PHOTOADDITION OF NUCLEOPHILES TO URACIL
Author(s) -
SUMMERS W. A.,
ENWALL C.,
BURR J. G.,
LETSINGER R. L.
Publication year - 1973
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1973.tb06357.x
Subject(s) - chemistry , nucleophile , photochemistry , uracil , bromide , hydrazine (antidepressant) , thiocyanate , azide , iodide , medicinal chemistry , inorganic chemistry , organic chemistry , dna , biochemistry , chromatography , catalysis
— Quantum yields for 254 nm ultraviolet photoaddition of the nucleophiles hydrazine, HCN, HSO 3 ‐ , methyl amine, and BH 4 ‐ to uracil have been measured; the quantum yields for hydrazine, HCN, and HSO 3 ‐ additions are pH‐dependent. The nucleophiles sulfide, azide, chloride, bromide, iodide, nitrite and thiocyanate failed to photo–add under similar conditions. These reactions are interpreted as 1,4‐additions to the conjugated enone system of the anti‐aromatic compound, uracil; as suggested by S. Y. Wang (Wang and Nnadi, 1968). The nuclear magnetic resonance (NMR) spectrum of the photohydrate of uracil‐5‐d‐showed that the proton was added to the 5‐position in a stereochemically random manner. The photoaddition of HSO 3 ‐ takes place at much lower concentrations than required for the thermal addition of this anion and is also stereochemically random.