2025 Volume 73 Issue 8 Pages 707-712
Prealnumycin B is an aromatic polyketide characterized as a reduced form of prealnumycin with a 6S-alcohol. As an extension of our earlier work on the synthesis of prealnumycin, the C7–C8 double bond was hydrogenated using Wilkinson’s catalyst, and the C6 carbonyl group was stereoselectively reduced via asymmetric transfer hydrogenation with the (S,S)-Ts-DENEB catalyst, where the use of methanol as a solvent was crucial for achieving high regioselectivity. By comparing its spectroscopic data with those of the natural isolate, the absolute configuration of prealnumycin B was determined to be 1R,6S. In addition, the antibacterial activities of prealnumycin B and related compounds were evaluated.