6-Magnesiated purines: preparation and reaction with aldehydes.
[reaction: see text] Halogen-metal exchange reaction of 9-benzyl-6-iodopurine with iPrMgCl in toluene at -80 degrees C proceeds almost quantitatively. Such a purine-derived Grignard reagent reacts selectively with aldehydes in toluene, giving the corresponding alcohols in 25-62% yield, while other functional groups such as ketones, esters, and nitriles do not react under these conditions. The reaction can be extended to protected 6-iodopurine ribonucleoside.
Department of Organic Chemistry, Prague Institute of Chemical Technology, Technická 5, 166 28 Prague 6, Czech Republic.
Tomás
T
Tobrman
Dalimil
D
Dvorák