A concise and efficient approach was established for the divergent total synthesis of (±)-tanshindiol B and C and tanshinone I from a ubiquitous ene intermediate in 1–2 steps. This critical intermediate was derived from (±)-tanshinol B, which was synthesized in 50% overall yield over 3 steps using an ultrasound-promoted cycloaddition as a key step. Compared to a previously reported strategy, our approach is more step-economic, thus greatly improving the synthetic efficiency. The bioactivity evaluation indicates that the diol stereochemistry of the tanshidiols has an impact on the EZH2 inhibitory activity.

中文翻译：

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（±）-丹参醇B，丹参酮I和（±）-丹参二醇B和C的总合成†

建立了一种简捷有效的方法，以1至2个步骤从无处不在的烯中间体分步进行总合成（±）-丹参二醇B和C和丹参酮I。该关键中间体衍生自（±）-丹参酚B，使用超声波促进的环加成反应为关键步骤，可在3个步骤中以50％的总收率合成。与以前报告的策略相比，我们的方法更具阶梯性，从而大大提高了合成效率。生物活性评估表明，丹参二醇的二醇立体化学对EZH2抑制活性有影响。