نتایج جستجو برای: preparation of ethers
تعداد نتایج: 21171003 فیلتر نتایج به سال:
A novel and non-ODS-based (ODS = ozone-depleting substance) preparation of 2-chloro-2,2-difluoroacetophenone (1) was achieved in high yield by using 2,2,2-trifluoroacetophenone as the starting material. Compound 1 was found to act as a good difluorocarbene reagent, which readily reacts with a variety of structurally diverse phenol derivatives 4 in the presence of potassium hydroxide or potassiu...
We have discovered a mild, catalytic protocol for the regio- and stereoselective synthesis of trisubstituted allyl diarylphosphonates from the corresponding disubstituted allyl silyl ethers, circumventing the challenges related to the preparation and availability of stereodefined trisubstituted olefins. A closely related arylation reaction was also discovered during the methodology development....
A novel and stereo-controlled method for the preparation of functionalized macrolactams was developed. The process involves stereoselective enol ether formation, followed by an azacyclic ring expansion via an aza-Claisen rearrangement. Herewith, we describe a systematic investigation of an aza-Claisen rearrangement-induced ring expansion of azacycles prepared by appending E/Z-enol ethers to the...
The selective preparation of monobenzyl glyceryl ethers, which are potential commodity chemicals with special functions, was explored to find new applications for glycerol. Among the acid catalysts investigated (sulfuric acid, heteropoly acid, Nafion(R), and zeolite), Zeolite Socony Mobil-5 (ZSM-5) afforded better results. The reaction of equimolar amounts of glycerol and benzyl alcohol at 150º...
A mild and efficient protocol for the deprotection of silyl ethers using KF in tetraethylene glycol is reported. A wide range of alcoholic silyl ethers can be selectively cleaved in high yield in the presence of certain acid- and base-labile functional groups. Moreover, the phenolic silyl ethers were cleaved exclusively, without affecting the alcoholic silyl ethers, at room temperature.
Pieces of the digestive gland of the starfish, Asterias forbesi, were incubated in vitro with various radioactive lipid precursors in order to follow the biosynthesis of the alkyl and alkenyl glycerol ethers. Acetate-1-14C was incorporated readily into alkyl glycerol ethers of both neutral lipid and phospholipid fractions, but very poorly into the alkenyl glycerol ethers. Stearic acid-l-14C and...
Homoallenic alcohols are prepared from propargyl vinyl ethers using a trinuclear gold(I)-oxo complex, [(Ph3PAu)3O]BF4, as a catalyst for propargyl Claisen rearrangement at room temperature. The gold(I)-catalyzed reaction is effective for a diverse collection of propargyl vinyl ethers, including substrates containing aryl and alkyl groups at the propargylic position, and hydrogen, aryl, and alky...
Formation of natural gas hydrate is a serious problem in the gas and oil industry because it can plug pipelines and destroy the equipment. This study aimes to evaluate the concentration effect of glycol ethers on their synergism with a commercial kinetic hydrate inhibitor (Luvicap 55W) in sweet natural gas-water systems at a constant temperature of 4 oC and pressure of 95 bar. Hydrate formation...
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