Total Synthesis and Structural Revision of (-)-Garvensintriol

The stereoselective total synthesis and structure revision of (-)-garvensintriol, a cytotoxic styryllactone from Goniothalamus arvensis, has been accomplished. Through meticulous synthetic efforts, single-crystal X-ray diffraction analyses, and DFT calculations, we revised the stereochemistry of C-5 and C-6 in the originally proposed structure of garvensintriol and established the correct structure as a five-membered γ-butyrolactone, rather than the previously assigned saturated δ-lactone. The revised structure of (-)-garvensintriol was unambiguously confirmed by its chemical synthesis. In addition, our revised garvensintriol displays identical spectral data with those reported for another naturally occurring styryllactone, (-)-3-deoxycardiobutanolide, suggesting that (+)-garvensintriol and (-)-3-deoxycardiobutanolide are, in fact, the same natural product.