Total Synthesis of Gymnothelignan K via a One-Pot Homologative γ‑Butyrolactonization

The first total synthesis of tetrahydrofuran dilignan gymnothelignan K is disclosed. The approach is based on implementing an early stage one-carbon homologative lactonization, which we recently disclosed, for constructing the γ-butyrolactone scaffold with the requisite β,γ-trans-vicinal stereocenters. Other salient features of the synthesis include the acid-promoted dimerization and the Suzuki–Miyaura cross-coupling reaction to install the challenging diaryl skeleton that permits the effective assembly of the optically active gymnothelignan K in 8 steps from commercially available materials.本研究首次报道了四氢呋喃二木脂素裸子脂素K（gymnothelignan K）的全合成路线。该策略采用我们近期报道的早期阶段单碳同系化内酯化反应，用于构建带有所需β,γ-反式邻位立体中心的γ-丁内酯骨架。该合成的其他显著特征包括：通过酸促二聚反应与铃木-宫浦（Suzuki–Miyaura）交叉偶联反应构建具有挑战性的二芳基骨架，从而可从市售原料出发，经8步反应高效组装得到光学活性的裸子脂素K。