Tracer studies of acid-catalyzed reactions. XI. Stereoselectivity in alcohol dehydration over hydroxyapatite and alumina catalysts

Abstract

over MgSOi and concentrated. The remaining oil produced under vacuum solid sulfoximide, 0.43 g (46%), which was recrystallized from ethyl acetate at -78°to give 0.26 g of the hygroscopic sulfoximide 5.Thiane-l-(iV-tosyl)iniide 1-Oxide (8). Tosyl chloride (2.15 g) and thian-l-imide 1-oxide (5, 0.75 g) were stirred in 30 ml of dry pyridine at room temperature for 24 hr. Water was added, and the mixture was extracted with CHCla. Evaporation of the CHC13 produced a yellow liquid, to which toluene was added in order to remove the pyridine as an azeotrope. The volume was reduced in this manner to about 5 ml. Concentration under reduced pressure left a white solid, which was recrystallized from ethyl acetate to give 1.2 g (75%) of white crystals, mp 136-137°.

Novel Silver Loaded Hydroxyapatite Catalyst for the Selective Catalytic Reduction of NOx by Propene

“…Owing to its unique acid-base properties, hydroxyapatite attracted much attention as solid catalyst more recently for various reactions such as dehydration and dehydrogenation of alcohols [8,9], oxidation of alkanes [10,11], Knoevenagel condensation [12], Friedel-Crafts alkylation [13], and Michael addition [14] and WGS reaction [15]. Hydroxyapatite is also used as a catalyst support for transition metal catalysts in various types of oxidation and carbon-carbon bond forming reactions [16].…”

Selective oxidation of alcohols with oxygen on Ru–Co-hydroxyapatite: A mechanistic study

“…The acid-base properties of hydroxyapatite were used in various reactions including dehydration and dehydrogenation of alcohols [6,7], oxidation of alkanes [8,9], Knoevenagel condensation [10], Friedel-Crafts alkylation [11], and Michael addition [12]. Hydroxyapatite is used also as catalyst support for transition metal catalysts in various types of oxidation and carbon-carbon bond forming reactions [5].…”

Study of cyclohexanol decomposition reaction over the ferrospinels, A1−xCuxFe2O4 (A=Ni or Co and x=0, 0.3, 0.5, 0.7 and 1), prepared by ‘soft’ chemical methods

“…But, by examining the dehydration of methyl substituted CHOLs, two possible mechanistic schemes have been proposed [47,48]. One of these is similar to E 2 elimination in which the catalyst provides both an acidic site to attack the hydroxyl group and a basic site to abstract a proton.…”