Selective dehydration of 3β-hydroxy-5α-androstan-17-one over sulfonic acid-incorporated-MCM-41 mesoporous materials

Sulfonic acid-incorporated-MCM-41 mesoporous materials show exceptional yield and regioselectivity for Δ2-olefin in the dehydration of 3β-hydroxy-5α-androstan-17-one (epiandrosterone), due to its specific orientation on the sulfonic acid sites located on the surface of the large pores, allowing it to adopt a sufficiently tilted structure with small steric hindrance. The preferred orientation of epiandrosterone on the surface without any steric limitation was confirmed by theoretical calculation using a simplified surface model.