Florol synthesis via Prins cyclization over hierarchical beta zeolites

• Published in: Molecular catalysis 2022-10, Vol.531, p.112683, Article 112683
• Main Authors: Shcherban, Nataliya, Barakov, Roman, Lasne, Basile, Mäki-Arvela, Päivi, Shamzhy, Mariya, Bezverkhyy, Igor, Wärnå, Johan, Murzin, Dmitry Yu
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Florol, Acid sites; Hierarchical zeolite; or physical chemistry; Prins cyclisation; Tetrahydropyranol; Theoretical and
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.mcat.2022.112683

•Prins cyclization of isovaleraldehyde with isoprenol yielding tetrahydropyranol (Florol).•Hierarchical beta zeolites through hydrothermal treatment of a concentrated alkali metal-free zeolite gel-precursor.•The highest yield with moderate acidity, developed mesoporosity and a high external surface area.•Substituted tetrahydropyranol are formed over weak and medium Brønsted acid sites.•Kinetic analysis and numerical data fitting. A set of hierarchical beta zeolites with variable Si/Al ratios, nanoparticle sizes, textural and acidic properties was prepared using a hydrothermal treatment of a concentrated alkali metal-free protic acid-containing zeolite gel-precursor. The obtained catalysts were investigated in the Prins cyclization of isovaleraldehyde with isoprenol yielding a commercially valuable tetrahydropyranol (Florol). The highest yield of the desired product (55.4%) was achieved over a zeolite catalyst possessing moderate acidity, developed mesoporosity (Vmeso 0.60 cm3/g) and a high external surface area (290 m2/g). Preferable formation of substituted tetrahydropyranol over weak- and medium-strength Brønsted acid sites, on the one hand, and generation of the undesired dehydration products mainly over strong Brønsted acid sites, on the other hand, occurring in parallel routes were supported by the kinetic analysis of the reaction network. [Display omitted]