Síntese estereosseletiva e caracterização estrutural de compostos Z-enínicos acoplados a pseudoglicosídeos

Abstract

Polyunsaturated compounds of Z-configuration have been gaining prominence in medicinal chemistry due to the substantiation of biological activities of some molecules with this system. In parallel the glycosides are structures widely used as precursor blocks in the synthesis of biologically active molecules, because its stereochemistry in association with its anomeric effect facilitates the stereotyped understanding of the products formed in later reactions and structural modifications. The present work presents a strategy for the synthesis of Z-enynes based on the Sonogashira-type coupling reaction between Z-vinylic tellurides and pseudoglycosidic alkynes, obtaining products with excellent yields of a stereoselective form with probable antitumor activity against the biological evaluation of cells Tumor cells. The desired vinylic tellurides were prepared from the hydrotelluration reaction of different terminal alkynes with the Dibutyl telluride (BuTeTeBu) to yield compounds in good yields (85-91%). The 2,3-unsaturated O-glycosides were obtained through successive reactions, from D-glucose and different enyne alcohols, using a new method, which applies the ultrasonic bath as an energy source, achieving an excellent yield of the synthesized compounds (85-92%). Finally the Z-vinylic tellurides and the pseudoglycosides were subjected to a palladium catalyzed cross coupling to obtain the Z-enyne compounds in satisfactory yields (84-89%).