A. Baeza, J. Mendiola, C. Burgos
Oct 1, 2010
Citations
0
Influential Citations
16
Citations
Journal
European Journal of Organic Chemistry
Abstract
The reaction of protected 3-bromo-2-(bromomethyl)-4-methoxypyrrolo[2,3-b]pyridine and tosylmethyl isocyanide (TosMIC) afforded a pyrido[3',2':4,5]pyrrolo[1,2-c]pyrimidine derivative in good yield. This compound was transformed through installation of the pyrimidine moiety in the C5 position, hydrolysis, and decarboxylation in an advanced intermediate for the total or formal synthesis of the natural alkaloid variolin B. Reaction of 3-bromo-2-(bromomethyl)-4-chloropyrrolo[2,3-b]pyridine with N-tosylmethyl dichloroformimide as a synthetic TosMIC equivalent afforded trihalosubstituted pyrido[3',2':4,5]pyrrolo[1,2-c]pyrimidine. This compound was used in a new total synthesis of the alkaloid variolin B by selective and sequential C-N, C-C, and C-O palladium-mediated functionalization at the C9, C5, and C4 positions of the pyrido[3',2':4,5]pyrrolo[1,2-c]pyrimidine system. A formal synthesis of deoxyvariolin B is also described by using the same synthetic strategy.