PRODUCTION OF 2-SUBSTITUTED 4-METHYL-TETRAHYDROPYRANS FROM STARTING MATERIALS CONTAINING 2-ALKYL-4,4-DIMETHYL-1,3-DIOXANES
申请人:BASF SE
公开号:US20170037020A1
公开(公告)日:2017-02-09
The invention relates to a method for producing 2-substituted 4-methyltetrahydropyrans of general formula (I) from starting materials containing at least one 2-substituted 4,4-dimethyl-1,3-dioxane of general formula (II).
Heteropoly acid catalysts in Prins cyclization for the synthesis of Florol®
作者:Augusto L.P. de Meireles、Kelly A. da Silva Rocha、Elena F. Kozhevnikova、Ivan V. Kozhevnikov、Elena V. Gusevskaya
DOI:10.1016/j.mcat.2020.111382
日期:2021.2
H3PW12O40 heteropoly acid supported on SiO2 and its bulk acidic cesium salt Cs2.5H0.5PW12O40 are demonstrated to be highly active and recyclable solid catalysts for Prins cyclization allowing for the clean, high-yielding synthesis of Florol® from isoprenol and isovaleraldehyde. Florol®, a valuable floral odorant employed in a vast variety of commercial products, was obtained in ca. 80 % yield under
SiO 2上负载的H 3 PW 12 O 40杂多酸及其本体酸性铯盐Cs 2.5 H 0.5 PW 12 O 40是高活性且可回收的固体催化剂,可用于Prins环化反应,从而实现清洁,高产率的Florol合成®由异戊烯醇和异戊醛制成。Florol®是一种可在多种商业产品中使用的有价值的花香剂,大约在2000年获得。在接近环境条件下的收率为80%。用作绿色反应介质的碳酸二甲酯或碳酸二乙酯,催化剂用量低和适中的条件是有助于该方法可持续性的重要特征。
Florol synthesis via Prins cyclization over hierarchical beta zeolites
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 Prinscyclization of isovaleraldehyde with isoprenol yielding a commercially valuable tetrahydropyranol (Florol). The
使用水热处理浓缩的不含碱金属质子酸的沸石凝胶前体,制备了一组具有可变 Si/Al 比、纳米颗粒尺寸、结构和酸性特性的分级 β 沸石。所获得的催化剂在异戊醛与异戊二烯醇的普林斯环化中进行了研究,产生了具有商业价值的四氢吡喃醇 (Florol)。所需产物的最高产率 (55.4%) 在具有中等酸度、发达的中孔 ( V meso 0.60 cm 3 /g) 和高外表面积 (290 m 2 ) 的沸石催化剂上实现/G)。一方面,在弱和中等强度的布朗斯台德酸位点上优选形成取代的四氢吡喃醇,另一方面,主要在强布朗斯台德酸位点上生成不需要的脱水产物,动力学分析支持平行路线发生的反应网络。
1,2-Elimination of alcohol from homoallyl ethers under the influence of mixed metal bases