Chemoenzymatic asymmetric total synthesis of naturally occurring resorcylic acid lactones hamigeromycins F and G.

Asymmetric total synthesis of two naturally occurring resorcylic acid lactones (RALs), hamigeromycins F and G, was achieved for the first time. The synthetic strategy involved a late-stage intramolecular macrolactonization achieved with a transesterification reaction. Stereocenters (C 10' and C 6' ) in both the molecules were accessed via an enzymatic kinetic resolution reaction. The penta-substituted aromatic core present in hamigeromycins F and G was accessed using vanillin as a precursor. The crucial E -olefinic unsaturated bond at C 1' -C 2' was constructed with a stereoselective Julia-Kocienski olefination reaction.