This article describes a robust and large-scale synthesis of the ketosteroid building block 11β-hydroxyandrosterone (2) from cheap and readily available hydrocortisone (1). The initial discovery route, which was conducted on a gram scale and achieved a 3–6% yield over eight steps, is also described. Key to the route redesign was the incorporation of two stereoselective steps setting the desired 5α-H and 3α-OH chiral centers and optimization to minimize chromatographic purification. The process route was then conducted at the kilogram scale and achieved a 21–28% yield over four steps.

中文翻译：

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11β-羟基雄酮的公斤级合成

本文介绍了从廉价且容易获得的氢化可的松 (1) 中大规模大规模合成酮类固醇结构单元 11β-羟基雄甾酮 (2)。还描述了最初的发现路线，该路线以克为单位进行，经过八个步骤实现了 3-6% 的产率。路线重新设计的关键是合并两个立体选择性步骤，设置所需的 5α-H 和 3α-OH 手性中心，并进行优化以最大程度地减少色谱纯化。然后，该工艺路线在千克规模上进行，通过四个步骤实现了 21-28% 的产率。