Methyl Ether Mixtures Research Articles

Pervaporation Separation of Methanol from Methanol-t-Amyl Methyl Ether Mixture by Polyion Complex Membrane.

Pervaporation separation of methanol (MeOH) from methanol-t-amyl methyl ether (TAME) mixtures is carried out using polyion complex (PIC) hollow fiber membrane. The sorption experiment is performed to observe the equilibrium relations between solute concentrations in the solution and in the membrane phase. With increasing MeOH weight fraction in the feed solution, the permeation flux of MeOH increases, but that of TAME remains almost constant. Considering the swelling effect by MeOH component, the flux model is described using diffusion coefficients dependent on MeOH concentration in the membrane and it can be successfully fitted to experimental data. The separation factor of MeOH ranges from 12 to 73, and decreases with increasing MeOH weight fraction in the feed solution.

Superacid isomerization of phylloclandene, isophylloclandene, and phylloclandanol

It has been established that, on interaction with a superacid, phyllocladene (XI), isophyllocladene (XV), and phyllocladan-16-ol (XIX) give identical mixtures of substances which include phyllocladene (XI), isophyllocladene (XV), neoisoatisene (XX), tetracyclic hydrocarbons with a new carbon skeleton (XXI) and (XXII), and a mixture of methyl ethers of alcohols formed as the result of the addition of methanol to the carbocations arising on the protonation of the above-mentioned hydrocarbons.

Synthesis of methyl ethers of methyl 2-acetamido-2-deoxy-α-D-glucopyranoside

A convenient method is proposed for the synthesis of all the individual methyl ethers of methyl 2-acetamido-2-deoxy-α-D-glucopyranoside based on the partial methylation of 2-acetamido-2-deoxy-α-D-glucopyranoside with dimethyl sulfate in an alkaline medium followed by preparative liquid column chromatography on silica gel of the resulting mixture of methyl ethers.

Partial methylation of methyl glycosides: A source of samples for analysis of methylation of carbohydrate-containing compounds

Methyl ether mixtures were obtained by partial methylation of 15 methyl glycopyranosides using Purdie's procedure. Identification of ethers as acetates by gas-liquid chromatography-mass spectroscopy (glc-ms) techniques allowed us to assume them to be sample sources for methylation analysis. T-values were tabulated using a scale ranging from permethyl ether- (0) to peracetate methyl glycosides (100) for subsequent identification with the aid of glc in NPGS and QF-1 liquid phases. A scheme has been devised for isolating individual methyl ethers by preparative glc.