Stereoselective synthesis of the right-hand cores of 16-methylated oxazolomycins

Abstract The right-hand heterocyclic cores of oxazolomycins having either 16 R or 16 S -methyl group configurations on the β-lactones were stereoselectively synthesized from the common intermediate utilized for our previous syntheses of neooxazolomycin and oxazolomycin A. In addition, the right-hand segment required for the synthesis of KSM-2690 and lajollamycin members was also synthesized in a stereoselective manner.