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。