Biosynthetic Origin of the Oxygen Atoms of Tetracenomycin C

Abstract

Water and not acetate is the source of the oxygen atom 4a-OH in the biosynthesis of tetracenomycin C. Based on this unusual finding, an intermediate epoxide is postulated, which has to be “cis opened” to attain the required stereochemistry at C-4a and C-12a (see reaction sequence below).