Alpha-carboxy-6-nitroveratryl: a photolabile protecting group for carboxylic acids.
The synthesis of a new photolabile protecting group for carboxylic acids, alpha-carboxy-6-nitroveratryl (alphaCNV), is described. Bromide 3, prepared in four steps from 3,4-dimethoxyphenylacetic acid, was used to alkylate carboxylic acids under mild conditions in good yield. Palladium-catalyzed deallylation afforded the acids 4a-h, which underwent rapid and quantitative photolysis at wavelengths longer than 300 nm to liberate the carboxylic acid in good to quantitative yield. The rate of photolysis and quantum yield were determined to be 325 s(-1) and 0.17.
Russell
Alexander G
AG
School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
Ragoussi
Maria-Eleni
ME
Ramalho
Rui
R
Wharton
Christopher W
CW
Carteau
David
D
Bassani
Dario M
DM
Snaith
John S
JS
D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D009574:Nitro Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D010777:Photochemistry; D010782:Photolysis; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet
D002264:Carboxylic Acids; D009574:Nitro Compounds; C553213:alpha-carboxy-6-nitroveratryl