A novel and simple route was developed that gives sparstolonin B in high yields from affordable commercial compounds. A Diels–Alder strategy was used for the facile construction of the multisubstituted diphenyl ether. The xanthenone segment was obtained by cyclization in an intramolecular Friedel–Crafts reaction, followed by selective reduction of a ketone group and a transformation from a hydroxy group into a cyano group. The final part of the lactone was directly derived by the reduction of the cyano group with Raney nickel.
Key words
sparstolonin B - xanthenone - lactone - total synthesis - medicinal chemistry
