synthetic microgrewiapine A) followed by O-acetylation, exhibit NMR data that are identical to those of the authentic sample. The previous report that this two-step transformation proceeds with epimerization at C-6 is thus shown to be in error: the purported sample of O-acetyl 6-epi-microgrewiapine A is structurally misassigned and is, in fact, O-acetyl microgrewiapine A. A plausible rationale for the
研究了O-乙酰 microgrewiapine A的形成。对源自
天然产物的真实样品的 NMR 数据进行校正。由合成 microcosamine A 的还原性N-甲基化(产生合成 microgrewiapine A)然后O-乙酰化产生的全合成样品显示出与真实样品相同的 NMR 数据。先前的报告表明,这种两步转化在 C-6 处进行差向异构化是错误的:据称O-乙酰 6 - epi -microgrewiapine A 的样品在结构上分配错误,实际上是O-乙酰 microgrewiapine A. 提出了结构错配的合理理由。