BF3 x Et2O-mediated cascade cyclizations: synthesis of schweinfurthins F and G.

ABSTRACT: The total synthesis of the natural stilbene (+)-schweinfurthin G (8) has been accomplished through a sequence based on an efficient cationic cascade cyclization. This cascade process is initiated by Lewis acid promoted ring opening of an epoxide and terminated through a novel reaction with a phenolic oxygen "protected" as its MOM ether. Several Lewis acids have been examined for their ability to induce this new reaction, and BF3 x Et2O was found to be the most effective. The only major byproduct under these conditions was one where the expected secondary alcohol was found as its MOM ether derivative (e.g., 30). While this byproduct could be converted to the original target compound through hydrolysis, it also could be employed as a protected alcohol to allow preparation of a benzylic phosp

SUBMITTER: Mente NR 

PROVIDER: S-EPMC5520577 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature