Carbonyl compounds 1 were converted to the corresponding 1,3-dioxolanes 2 and 1,3-dioxanes 4 with ethylene glycol and 2,2-dimethyl-1,3-propandiol, respectively, in the presence of 1-3 mol% of N-(benzyl, 4-methylbenzyl or 4-methoxybenzyl)-2(or -4)-cyanopyridinium hexafluoroantimonates 3. The catalyst 3d was also effective for the tetrahydropyranylation.
Synthesis of dioxolanes and oxazolidines by silica gel catalysis
作者:Taoufik Rohand、Jérôme Savary、István E. Markó
DOI:10.1007/s00706-018-2198-7
日期:2018.8
AbstractEthylene glycol condensed with carbonyl compounds in the presence of silicagel or alumina, without solvent and under pressure, affords 1,3-dioxolanes. 2-Amino-2-methylpropanol also condensed with carbonyl compounds in the presence of silicagel or an acid-activated clay, without solvent and under pressure, produces oxazolidines. To explain these results, we propose that the glycol and the
The titanium cation-exchanged montmorillonite efficiently catalyzed the selective acetalization of various carbonyl compounds as a recyclable solid acid. This heterogeneous catalyst has an advantage of a strikingly simple workup procedure over conventional homogeneous acids. (C) 2001 Elsevier Science Ltd. All rights reserved.
1,3-Dioxolanes from carbonyl compounds over zeolite HSZ-360 as a reusable, heterogeneous catalyst
Carbonyl compounds are converted, in good yields, into their 1,3-dioxolanes over zeolite HSZ-360, as a new reusable catalyst. Good chemoselectivity is also observed. (C) 1998 Elsevier Science Ltd. All rights reserved.
Magnetic isotope effects in photochemical reactions. Observation of carbonyl oxygen-17 hyperfine coupling to phenylacetyl and benzoyl radicals. Oxygen-17 enrichment studies