2081-44-9Relevant articles and documents
Tetrahydro-4 H-pyran-4-one: From the Laboratory Scale to Pilot Plant Manufacture
Zahim, Sara,Delacroix, Kenny,Carlier, Agathe,Berranger, Thierry,Bergraser, Julie,Echeverria, Pierre-Georges,Petit, Laurent
, p. 199 - 206 (2022/01/12)
This study describes our recent efforts to find an efficient and scalable route to tetrahydro-4H-pyran-4-one using the commercially available starting materials. The route scouting work and the full development of an efficient access to the target are described. This work culminated in the preparation of above 20 kg of the title compound in our pilot plant facility.
Zeolite-Catalyzed Formaldehyde–Propylene Prins Condensation
Vasiliadou, Efterpi S.,Gould, Nicholas S.,Lobo, Raul F.
, p. 4417 - 4425 (2017/11/20)
Prins condensation of formaldehyde with propylene to form 3-buten-1-ol is investigated using microporous solid acid catalysts. Zn/H-beta shows high conversion but leads to a broad product distribution composed primarily of pyrans. Mechanistic studies revealed that 3-buten-1-ol reacts via Prins cyclization or dehydrate to 1,3-butadiene that further reacts with formaldehyde via a hetero-Diels–Alder reaction. These secondary reactions are suppressed over ZSM-5 catalysts: 3-buten-1-ol is the predominant product over H-ZSM-5 zeolite under all conditions investigated. 3-Buten-1-ol selectivity of up to 75 % is achieved. In a second step 3-buten-1-ol dehydrates at temperatures as low as 423 K, forming 1,3-butadiene. Although Br?nsted acid sites are the primary catalytic sites, ion exchange of ZnII increases the overall rate and 3-buten-1-ol selectivity. H-ZSM-5 showed significant differences in reactivity and selectivity as a function of the Si/Al ratio; optimal catalytic properties were observed within Si/Al=40–140.
Heterogeneous ceria catalyst with water-tolerant Lewis acidic sites for one-pot synthesis of 1,3-diols via prins condensation and hydrolysis reactions
Wang, Yehong,Wang, Feng,Song, Qi,Xin, Qin,Xu, Shutao,Xu, Jie
, p. 1506 - 1515 (2013/03/28)
The use of a heterogeneous Lewis acid catalyst, which is insoluble and easily separable during the reaction, is a promising option for hydrolysis reactions from both environmental and practical viewpoints. In this study, ceria showed excellent catalytic activity in the hydrolysis of 4-methyl-1,3-dioxane to 1,3-butanediol in 95% yield and in the one-pot synthesis of 1,3-butanediol from propylene and formaldehyde via Prins condensation and hydrolysis reactions in an overall yield of 60%. In-depth investigations revealed that ceria is a water-tolerant Lewis acid catalyst, which has seldom been reported previously. The ceria catalysts showed rather unusual high activity in hydrolysis, with a turnover number (TON) of 260, which is rather high for bulk oxide catalysts, whose TONs are usually less than 100. Our conclusion that ceria functions as a Lewis acid catalyst in hydrolysis reactions is firmly supported by thorough characterizations with IR and Raman spectroscopy, acidity measurements with IR and 31P magic-angle-spinning NMR spectroscopy, Na+/H + exchange tests, analyses using the in situ active-site capping method, and isotope-labeling studies. A relationship between surface vacancy sites and catalytic activity has been established. CeO2(111) has been confirmed to be the catalytically active crystalline facet for hydrolysis. Water has been found to be associatively adsorbed on oxygen vacancy sites with medium strength, which does not lead to water dissociation to form stable hydroxides. This explains why the ceria catalyst is water-tolerant.
