Concise synthesis of 7-dehydrocholesterol and 25-hydroxy-7-dehydrocholesterol

7-Dehydrocholesterol (7-DHC) and its hydroxylated product, 25-hydroxy-7-dehydrocholesterol (25-OH-7-DHC), exhibit diverse biological activities and serve as key precursors in the industrial synthesis of vitamin D₃ (VD₃) and 25-hydroxyvitamin D₃ (25-OH-VD₃). Consequently, various synthetic routes for 7-DHC and 25-OH-7-DHC have been proposed. Herein, we report a concise and practical synthetic route to 7-DHC (64% total yield) and 25-OH-7-DHC (44% total yield), using commercially available cholesterol and 25-hydroxycholesterol as the starting materials, respectively. The key reaction conditions, including solvent choice, temperature, base, and additive, were systematically investigated and optimized. This innovative synthetic route provides a cost-effective strategy for the potential large-scale production of 7-DHC and 25-OH-7-DHC.