Synthetic (±)-spirobrassinin (1) was enantioresolved by a chiral auxiliary method giving (+)-1 and natural (−)-1. The absolute configuration was unambiguously determined by X-ray crystallography of a (1′S,4′R)-camphanoyl derivative of (+)-1. Consequently, natural (−)-1 has an S configuration. Their CD spectra supported this result.
合成的 (±)-spirobrassinin (1) 通过手性辅助方法对映体分解,得到 (+)-1 和天然 (-)-1。绝对构型由 (+)-1 的 (1'S,4'R)-莰酰衍生物的 X 射线晶体学明确确定。因此,自然 (-)-1 具有 S 构型。他们的 CD 光谱支持了这一结果。
Preparation of cruciferous phytoalexin related metabolites, (−)-dioxibrassinin and (−)-3-cyanomethyl-3-hydroxyoxindole, and determination of their absolute configurations by vibrational circular dichroism (VCD)
作者:Kenji Monde、Tohru Taniguchi、Nobuaki Miura、Shin-Ichiro Nishimura、Nobuyuki Harada、Rina K Dukor、Laurence A Nafie
DOI:10.1016/s0040-4039(03)01513-2
日期:2003.8
metabolites, (−)-dioxibrassinin (1) and (−)-3-cyanomethyl-3-hydroxyoxindole (2) were prepared from isatin as racemates and were resolved by chiral HPLC. Their absoluteconfigurations were determined by the new chiroptical technique, vibrationalcirculardichroism (VCD), as well as by the conventional electronic circulardichroism (ECD). It is concluded that the absoluteconfigurations of the naturally
Brassicanal C, a new sulphur-containing phytoalexin, and two dioxindoles were isolated from cabbage inoculated with Pseudomonas cichorii. Brassicanal C was shown to possess a unique sulphinate structure on the basis of spectroscopic data and optical activity. One of the dioxindoles, dioxibrassinin, appears structurally to be a possible precursor to spirobrassinin.
US8933248B2
申请人:——
公开号:US8933248B2
公开(公告)日:2015-01-13
Soledade, M.; Pedras, C.; Okanga, Francis I., Chemical Communications, 1998, # 1, p. 67 - 68