Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto, 607-8412, Japan.
J Nat Med. 2021 Mar;75(2):308-318. doi: 10.1007/s11418-020-01468-9. Epub 2021 Jan 3.
The enantioselective synthesis of (S)-(-)-spirobrassinin, which features a unique sulfur-containing spirooxindole skeleton, was achieved by focusing on the phytoalexin generation in Brassicaceae plants. Specifically, (S)-(-)-spirobrassinin was obtained in a one-pot fashion from L-tryptophan through a reaction involving S-spirocyclization with various turnip enzymes and constituents, i.e., using the turnip as a reaction reagent, catalyst, and reaction vessel. Surprisingly, this strategy also enabled the one-pot enantioselective synthesis of the novel non-natural spirooxindole (S)-(-)-5-methylspirobrassinin from 5-methyl-DL-tryptophan.
通过关注植物中植物抗毒素的产生，实现了具有独特含硫螺吲哚骨架的（S）-（-）-螺[吲哚啉-3,4-吡咯]-2,5-二酮的对映选择性合成。具体而言，（S）-（-）-螺[吲哚啉-3,4-吡咯]-2,5-二酮可由 L-色氨酸一锅法合成，涉及与各种芜菁酶和成分的 S-螺环化反应，即使用芜菁作为反应试剂、催化剂和反应容器。令人惊讶的是，该策略还能够从 5-甲基-DL-色氨酸一锅法对映选择性合成新型非天然螺吲哚（S）-（-）-5-甲基螺[吲哚啉-3,4-吡咯]-2,5-二酮。
