Enantioselective synthesis of the C1-C11 fragment of bafilomycin A1 using non-wittig and desymmetrization strategies

Jean-Christophe Poupon (1) , Emmanuel Demont (1) , Joëlle Prunet (1) , Jean-Pierre Férézou (1)

1 DCSO - Laboratoire de synthèse organique

The synthesis of the C1-C11 fragment 33 of bafilomycin A1 was achieved. Intermediate ketone 16 was prepared in six steps from 4-oxopimelate 13. Desymmetrization of this ketone using Koga's chiral base followed by TMSCl quench furnished silyl enol ether 17 with excellent enantioselectivity. Further elaboration led to C5-C11 aldehyde 24, which was coupled with sulfone 3 to give lactone 25 in very good yield. The subsequent reductive elimination created the E-trisubstituted C4-C5 olefin with a 13:1 selectivity. The E C2-C3 double bond was then installed by methanol elimination, and compound 33 was obtained after a few functional group manipulations and a Negishi methyl zirconation.

Jean-Christophe Poupon, Emmanuel Demont, Joëlle Prunet, Jean-Pierre Férézou. Enantioselective synthesis of the C1-C11 fragment of bafilomycin A1 using non-wittig and desymmetrization strategies. Journal of Organic Chemistry, 2003, 68 (12), pp.4700-4707. ⟨10.1021/jo034018e⟩. ⟨hal-00954829⟩