Synthesis of Labdane Diterpenes Galanal A and B from (+)-Sclareolide

The
first chemical synthesis of galanal A and B was achieved by a concise
and highly efficient pathway starting from commercially available
(+)-sclareolide and features a Wittig reaction and a titanocene-mediated
radical cyclization as the key steps.

以市售可得的(+)-香紫苏内酯（(+)-sclareolide）为起始原料，通过一条简洁高效的合成路径，首次完成了半缩醛A与B（galanal A and B）的化学合成，该合成路线以维蒂希反应（Wittig reaction）与钛茂介导的自由基环化反应（titanocene-mediated radical cyclization）作为关键步骤。