1 0 0 0 大環状抗生物質ナクチン類の構造研究
1 0 0 0 OA 42 新抗生物質Ascofuranone分子の絶対配置
- 著者
- 安藤 邦雄 佐々木 弘 細川 知良 縄田 喜治
- 出版者
- 天然有機化合物討論会実行委員会
- 雑誌
- 天然有機化合物討論会講演要旨集 18 (ISSN:24331856)
- 巻号頁・発行日
- pp.317-323, 1974-10-01 (Released:2017-08-18)
Molecular structure and absolute configuration of 4-o-ethyl ascofuranone (C_<23>H_<28>O_5Cl・C_2H_5) were determined by X-ray crystal structure analysis. Crystal structure was solved by the multisolution method. Dihydro-2,2-dimethyl-furan-3-one ring in the molecule adopts an envelope conformation, and the spatial configuration around the asymmetric carbon on the ring is Sinister according to the notation by Cahn, Ingold and Prelog. ORD and CD spectra were consistent with the ketone octant rule which predicted negative Cotton effect for the carbonyl n-π transition. Proton NMR spectra indicated that the ring was rigid, and its conformation in the solution was approximately identical to that in the crystal. All these results are the first stereochemical data on dihydro-2,2-dimethyl-furan-3-one ring in natural product.