We have achieved a total synthesis of telomestatin, and its absolute configuration was determined to be (R). Coupling of cysteine-containing trisoxazole amine and serine-containing trisoxazole carboxylic acid, followed by macrocyclization, provided a 24-membered diamide. The seventh oxazole ring was formed by a Shin's procedure via dehydroamide. Cyclodehydration of a modified (R)-cysteine-(S-tBu) moiety using Kelly's method (PPh 3(O)-Tf2O) with anisole furnished (R)-telomestatin, whose CD spectrum was in good agreement with that of the natural product.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry