ANYTHING
with a synthesis procedure of MDA from helional amide
using the Schmidt reaction instead of the Hoffman rearrangement.

Have UTFSE'ed to hell and back.

Thank YOU!
Pbint

Laboratory Preparation of Lithium Metal by Vacuum Metallurgy

W.J. Kroll & A.W. Schlechten

Minerals Technology
Vol.XIV, 1947, Tech. Pub. 2179

Abstract

As this paper is written, the only method for the commercial production of lithium metal is by the fusion electrolysis of LiCl-KCl mixtures, as first proposed by Guntz.2 The details of the industrial process have not been made public but Osborg8 stated that an efficiency of more than go pct is obtained with a lithium metal recovery above 95 pct and that the metal is 99.5 pct pure. Pletenev9 gave a power consumption of 66 kw-hr per kilogram of lithium metal produced with a salt consumption of 9 kg of LiCl and 0.4 kg of KCI. Pletenev's figures indicate a somewhat lower recovery than that given by Osborg. In a recent report on German lithium plants, Motock7 gives figures that are also less favorable than those reported by Osborg. At the German plants the lithium recovery in electrolysis was only 83.4 pct, with a power consumption of too kw-hr per kilogram of lithium. The metal averaged only 97 pct pure, with sodium and potassium as the chief impurities. The presence of SO2, SO3, Si02, Ba, Ca, and appreciable amounts of Na and Fe2O3 were especially disturbing in the electrolysis, and it was necessary to run the cell for some time to eliminate most of these impurities and condition the bath. It may be noted here that most of these impurities do not interfere with a thermal reduction process. These facts show that the present method of producing lithium is fairly efficient and would suggest that other methods could not compete. However, fusion electrolysis has certain drawbacks, such as the necessity of supplying costly, low-voltage direct current and of collecting and processing the anodic chlorine if it is not to be wasted. An even greater disadvantage is that lithium chloride must be used for an electrolyte. It is one of the most expensive salts of lithium, since it cannot be produced in anhydrous form by precipitation from aqueous solution, as is done with LiF or Li2CO3. The reduction of lithium by a vacuum process similar to the ferrosilicon method for the production of magnesium would have certain advantages. Small units, such as Pidgeon retorts, would give flexibility of production to meet demand, and a small plant would require moderate capital outlay. There is a possibility of using idle Government-owned magnesium plants for such purposes. The raw materials needed for vacuum thermal reduction would not have to be extremely pure, especially with respect to the iron and calcium content. This paper describes a series of experiments to determine the effectiveness of various agents for the reduction of lithium compounds.

Requested by no1uno



Kinetics and mechanisms of the acid degradation of the aldopentoses to furfural
Edward R. Garrett & Barry H. Dvorchik
J. Pharm. Sciences
Vol.58(7) 1969, pp.813-820
DOI: 10.1002/jps.2600580703

Abstract

The acid degradation of the aldopentoses to furfural and the degradation of furfural were followed spectrophotometrically and are first-order functions of HCI and pentose concentration. The aldopentose is largely transformed to furfural with small parallel reactions (7–25%). The furfural is subsequently degraded by specific hydrogen ion-catalyzed solvolysis to nonchromophoric products. The heats of activation were the same for the aldopentoses, 30 kcal./mole. The order of reactivities were ribose > xylose ~ lyxose > arabinose and in the ratio 5.4:2.2:2.2:1. The steric positioning of the hydroxyls in the reactive forms were the controlling factor. Free rotation of the hydroxyls in the open-chair form negates any steric requirements for this form. No correlation between steric factors and observed reactivities could be found for the furanose forms. The most plausible explanation of the order and magnitudes of the reactivities is that the rate-determining step is dehydration of the 3-OH, 2H or 4-OH, 5-H in those pyranose conformers amenable to axial-axial dehydration. The relative rates of dehydration are functions of the equilibrium concentrations of these reactive conformers and a specific reactivity which is a stereochemical function of the numbers of axial hydroxyls of such conformers. This explanation and the data are consistent with a positive entropic effect which implies that the transition state involves ring opening.

Requested by no1uno:

Selective isolation of anethole from fructus anisi stellati(star anise) by supercritical fluid extraction
Lin Kwok Liu
Anal. Commun. Vol.33(5) 1996, pp.175-176
DOI: 10.1039/AC9963300175

Abstract
Crude anethole over 90% purity (by GC) was obtained by extracting the ground star anise statically (10 min) and then dynamically (30 min) with supercritical carbon dioxide at a density of 0.35 g ml–1 and a temperature of 80 °C. Pure anethole (99% by GC) could be obtained by passing the crude anethole onto a column packed with a mixture of silica and activated charcoal and eluted with 2% ethyl acetate in petroleum ether.

Requested by no1uno:

Electrocchemicai oxidatiob of ketones in methanol in the presence of alkali metal bromides


L Gennady I. Nikishin, Michail N. Elinson & Irina V. Makhova

Tetrahedron.
Vol.47(4-5) 1991, pp.895-905
http://dx.doi.org/10.1016/S0040-4020(01)87078-2

Abstract

Electrochemical oxidation of methyl ketones in methanoi in the presence of alkali metal bromides affords methyl carboxylates. Benzyl alkyl ketones are transformed under similar conditions into methyl 3-phenylalkanoates, while ketones lacking s-benzyl or s-methyl group are oxidized into s-hydroxyketals.

 

Requested by Roid Rage:

Organoboron-Monosaccharides; X1. High-Yield Synthesis of a Bifunctionally Protected ?-D-Lyxofuranosyl Bromide
Wilhelm Volker Dahlhoff*, Roland Köster
Synthesis 1980; 1980(11): 936-937
DOI: 10.1055/s-1980-29279

and

Acid-catalysed isomerization of the tetraisopropyldisiloxane-1,3-diyl group. Simultaneous protection of two secondary alcoholic functions
C.H.M. Verdegaal, P.L. Jansse, J.F.M. de Rooij, J.H. van Boom
Tetrahedron Letters
Volume 21, Issue 16, 1980, Pages 1571–1574
DOI: 10.1016/S0040-4039(00)92778-3

are attached    As far as the first article, no doi exists because that journal has never been digitized:

https://lirias.kuleuven.be/handle/123456789/165518

thus it will have to be located in the stacks somewhere and scanned 

Requested by RoidRage



Synthesis of 2??O???d?Ribofuranosylnucleosides
Sergey N. Mikhailov1, Ekaterina V. Efimtseva1, Andrei A. Rodionov1, Georgii V. Bobkov1, Irina V. Kulikova1, Piet Herdewijn2
Current Protocols in Nucleic Acid Chemistry
DOI: 10.1002/0471142700.nc0114s27

Requested by no1uno


Investigation of LiAlH4–THF formation by direct hydrogenation of catalyzed Al and LiH
David Lacina, Liu Yang, Irinder Chopra, James Muckerman, Yves Chabalb and Jason Graetz
Phys. Chem.
Vol.14, 2012, pp.6569-6576
DOI: 10.1039/c2cp40493a

Abstract

The formation of LiAlH4–THF by direct hydrogenation of Al and LiH in tetrahydrofuran (THF) was investigated using spectroscopic and computational methods. The molecular structures and free energies of the various possible adducts (THF–AlH3, THF–LiH and THF–LiAlH4) present in a LiAlH4/THF solution were calculated and the dominant species were determined to be contact ion pairs where three THF molecules coordinate the lithium. Raman and X-ray absorption spectroscopy were used to investigate the effect of different Ti precursors on the formation of Al–H species and LiAlH4–THF and determine the optimal reaction conditions. A unique sample stage was developed from a microfluidic cell to evaluate the catalysts in situ. The effectiveness of two types of catalysts, titanium chloride (TiCl3) and titanium butoxide (Ti(C4H9O)4), and the catalyst concentration were evaluated under similar reaction conditions. Both catalysts were effective at facilitating hydrogenation, although TiCl3 was more effective over the first few cycles with the greatest kinetic enhancement achieved with a low concentration of around 0.15 mol%. These results were qualitatively supported by infrared spectroscopy, which indicated that although a small amount of Ti is necessary for disassociating H2, excess surface Ti (>0.1 ML) hinders the formation of Al–H species.

Requested by no1uno


The removal of oxygen from gas streams: applications in catalysis and gas chromatography
C R McLlwrick and C S Phillips
J. Phys. E: Scientific Instruments
Vol.6(12) 1973 pp.1208-
Doi:10.1088/0022-3735/6/12/034

Abstract

Manganese (11) oxide supported on Celite has been found to reduce the oxygen concentration in nitrogen streams to 1 part in 109.5, as measured by the resistance of a heated cobalt oxide filament. The supported manganese oxide has been used specifically to protect catalytic materials the properties of which are studied by using them as gas chromatographic columns. Its chromatographic and noncatalytic properties enable it where necessary to be packed directly into such columns.

Requested by RoidRage


Protection of 5??Hydroxy Functions of Nucleosides
H. Seliger
Current Protocols in Nucleic Acid Chemistry
DOI:  10.1002/0471142700.nc0203s00