Total synthesis of virgineone aglycone and stereochemical assignment of natural virgineone

The first total synthesis of virgineone aglycone has been achieved employing the tandem O-acylation–migration reaction and the olefin cross-metathesis as key steps for fragment couplings. The left-hand segment of virgineone was also synthesized. The absolute configuration of the reported virgineone aglycone was determined to be (2S,7RS,26S) based on NMR analyses and the specific rotation values of the synthetic compounds. The absolute configuration of the natural virgineone was presumed to be (2S,7S,26S) based on NMR analyses of the synthetic virgineone aglycone.