enantiomer of 175 yielded 10 % of ent-176 [108, 109] (Scheme 49). Interestingly,
primarily synthesized 176 was isolated in >40 % yield also applying the
Corey–Brunelle protocol indicating that this is a pivotal step [110].
Scheme 49 Corey–Brunelle conditions in the total synthesis of enterobactin, 177
Fig. 3 Reagents for thioester formation used in macrolactonizations
Synthesis of 12- to 16-Membered-Ring Lactones
407