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。
Diaklylaluminum chloride catalyzed ene reactions of aldehydes. Synthesis of ipsenol
作者:Barry B. Snider、David J. Rodini
DOI:10.1016/s0040-4039(00)92787-4
日期:1980.1
Dimethylaluminum chloride which is a mild Lewis acid and a proton scavenger, catalyzes the enereactions of aliphatic and aromatic aldehydes. Proton initiated rearrangements do not occur, since the alcohol-Lewis acid complex formed in the enereaction rapidly to give methane and a non-acidic aluminum alkoxide.
to that of dihydropyrans, after addition of water the results obtained by use of p -toluenesulfonic acid (ratio 3.5, selectivity 67 %) were comparable with those obtained by use of sulfuric acid and were better than those obtained by use of Amberlyst 15 (ratio 2.3, selectivity 68 %). A detailed study of the mechanism confirmed that addition of water to the doublebonds of dihydropyrans does not occur
PRODUCTION OF 2-SUBSTITUTED 4-HYDROXY-4-METHYL-TETRAHYDROPYRANS FROM STARTING MATERIALS CONTAINING 2-ALKYL-4,4-DIMETHYL-1,3-DIOXANES
申请人:BASF SE
公开号:US20170037022A1
公开(公告)日:2017-02-09
The present invention relates to a method for preparing 2-substituted 4-hydroxy-4-methyltetrahydropyrans from starting materials comprising at least one 2-alkyl-4,4-dimethyl-1,3-dioxane.