First total synthesis of (4R,5R,11S) and (4R,5R,11R)-iso-cladospolide B

Abstract

The two enantiomers of natural products (4S, 5S, 11R)-and (4S, 5S, 11S)-iso-cladospolide B have been synthesized and their structures unambiguously confirmed by X-ray crystallographic analysis. Key steps of the synthesis include the use of tri-O-acetyl-D-glucal as precursor for a chiral furan diol which, after side chain transformation, underwent singlet oxygen oxidation to afford the target butenolides