Asymmetric Total Syntheses of Aetheramides and Their Stereoisomers: Stereochemical Assignment of Aetheramides

The concise total syntheses of the potent HIV inhibitors aetheramides A and B (IC50 values of 15 and 18 nM), as well as three pairs of their stereoisomers, were achieved, which allowed the complete stereochemical assignment of aetheramides for the first time. With a longest linear sequence of 15 steps, the convergent, fully stereocontrolled route provided aetheramides A and B in 5.3% and 3.6% yields, respectively. The synthetic strategy features efficient Stille coupling for macrocyclization, asymmetric aldol reactions to establish the ambiguous stereochemistries at C-17 and C-26, and implementation of mild conditions to avoid the epimerization of the sensitive polyketide moiety and the migration of the labile lactone.