The asymmetric synthesis of chiral polycyclic ethers by an intramolecular [2+2] photocycloaddition is described.

Transformation of acetals into ethers by partial reduction using a samarium diiodide-Lewis acids-acetonitrile system is described. The reaction with aromatic acetals occurred in good yields in the presence of aluminum chloride (2 eq) whereas the corresponding aliphatic, vinylic, and alkynyl derivatives did not afford ethers under the same conditions. Beta-elimination to give an enol ether becom...

The propargyl Claisen rearrangement is a known protocol to gain access to functionalized allenes through the [3,3]-sigmatropic transformation of propargyl vinyl ethers. The correct use of appropriate propargyl vinyl ethers as starting materials coupled with suitable reaction conditions can aid in the development of new domino methodologies in which the allenes are valuable intermediates in rout...

The Au(I)-catalyzed cyclization of hydroxyallylic ethers to form tetrahydropyrans is reported. Employing (acetonitrile)[(o-biphenyl)di-tert-butylphosphine]gold(I) hexafluoroantimonate, the cyclization reactions were complete within minutes to hours, depending on the substrate. The reaction progress was monitored by GC, and comparisons between substrates demonstrate that reactions of allylic alc...

Evidence is presented for the existence of cholesteryl alk-1-enyl ethers in bovine and porcine cardiac muscle. Several different fatty chains are present in the cholesteryl ethers, the major species having 16 and 18 carbon atoms. The cholesteryl alk-1-enyl ether concentration was found to be 0.08 and 0.01 micro moles/100 mg of neutral lipid in bovine and porcine cardiac muscle, respectively.

A new procedure for the stereoselective synthesis of syn α-amino β-oxy ketones is reported. It consists of two steps; in the first step, α-amino silyl enol ethers having a (Z) geometry are prepared from 1-alkynes via 1-sulfonyl-1,2,3-triazoles. In the second step, the silyl enol ethers undergo the TiCl4-mediated Mukaiyama aldol reaction with aldehydes to produce α-amino β-oxy ketones with excel...

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...

Polybrominated diphenyl ethers (PBDEs) along with hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were found in plant and soil samples collected surrounding a seafood processing factory and a seafood market in China. The profiles of MeO-PBDE congeners were different between seafood processing factory and seafood market. The dete...

The parameters affecting the separation and quantification of trimethylsilyl ethers of mono- and diglycerides have been investigated by gas-liquid chromatography with QF-1 and SE-30 as stationary phases and a flame ionization detector. Results have been compared with those obtained earlier for triglycerides. The isothermal characteristics of a range of trimethylsilyl ethers of mono- and diglyce...

The direct α-arylation of cyclic and acyclic ethers with heteroarenes has been accomplished through the design of a photoredox-mediated CH functionalization pathway. Transiently generated α-oxyalkyl radicals, produced from a variety of widely available ethers through hydrogen atom transfer (HAT), were coupled with a range of electron-deficient heteroarenes in a Minisci-type mechanism. This mil...