TOTAL SYNTHESIS OF OXAZOLE-BASED VIRGINIAMYCIN ANTIBIOTICS - 14,15-ANHYDROPRISTINAMYCIN IIB

A total synthesis of 14,15-anhydropristinamycin IIB (3), a member of t he virginiamycin family of antibiotics (also known as streptogramins, pristinamycins or synergimycins) produced by Streptomyces is described . The synthesis is achieved from chiral, non-racemic starting material s and uses a convergent route involving synthesis of the substituted p roline 7 and the 4-oxazole carboxylic acid 8, their coupling to the vi nylstannane substituted vinyl bromide 6, and finally an intramolecular sp(2)-sp(2) Stille coupling reaction, i.e. 6 --> 22, to elaborate the macrocyclic core of the natural product.