Primary and secondary electrophilic radicals such as : .CHRCO2CH3(R=H,CH3,CO2CH3) and tertiary .CCl3, radical were added directly at C-8 of, the model purine compound, caffeine to give the corresponding 8-substituted derivatives in fairly good yields. Unexpected reaction of caffeine with oxy radicals from the initiators (PhCo2., t-BuOO.) gave rise to C-5 substituted 1,3,7-trimethyl-5,7-dihydrouric
Controlled C-5 methylation of caffeine by benzoyloxy radical addition at C-8
作者:J Zylber、L Ouazzani-Chahdi、A Chiaroni、C Riche
DOI:10.1016/s0040-4039(00)87833-8
日期:——
C-5 methylation of the model purine compound caffeine by acetyl benzoyl peroxide is the result of preferential addition of the electrophilic benzoyloxy radical at C-8 in neutral medium. X-ray structure and molecular orbital calculations on 1,3,5,7-tetramethyl-5,7-dihydrouric acid are presented.