STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES: XLIV. SYNTHESIS OF ISOMERIC BICYCLIC ACETAL ETHERS

1933 ◽  
Vol 8 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Earland G. Hallonquist ◽  
Harold Hibbert
Keyword(s):  
Organic Solvents ◽  
Potassium Hydroxide ◽  
New Method ◽  
Vapor Pressures ◽  
Open Chain ◽  
Cyclic Acetals ◽  
Aqueous Potassium Hydroxide ◽  
High Vapor

Two isomeric bicyclic acetal ethers, namely, 3, 5, 7-trioxabicyclo [2, 2, 2] octane and 3, 6, 8-trioxabicyclo [3, 2, 1] octane, have been synthesized by the action of aqueous potassium hydroxide on 1, 3-bromoethylidene glycerol 2-benzoate and 1, 2-bromoethylidene glycerol 3-benzoate respectively. Both isomers are crystalline products possessing similar solubilities in organic solvents and high vapor pressures. They show no indication of interconvertibility on solution in solvents, or under the influence of heat. On hydrolysis they yield glycollic aldehyde and glycerol.A new method for the synthesis of cyclic acetals from simple open-chain acetals is described.

Oxidation of Ethanol on Sn-Mo Oxide Catalysts

1992 ◽  
Vol 57 (3) ◽  
pp. 439-445
Author(s):  
Magdy A. Wassel ◽  
Nalla K. Allahaverdova ◽  
Tofki G. Alkhazov
Keyword(s):  
Acetic Acid ◽  
Potassium Hydroxide ◽  
Pulse Method ◽  
Conversion Ratio ◽  
Mo Catalyst ◽  
Acid Ratio ◽  
Aqueous Potassium Hydroxide ◽  
The Stability ◽  
Primary Oxidation ◽  
Oxidation Of Ethanol

To determine the acidic and basic properties of the title catalysts, the adsorption of NH3 and SO2 was compared using pulse method. It was found that this characteristics undergoes changes when the Sn-Mo catalyst is treated with aqueous potassium hydroxide solutions of different concentrations. The catalyst treated with the more concentrated KOH solution possesses mainly properties of a base. When studying the oxidation of ethanol it has been found that the αCO2/αaldehyde conversion ratio increases with the time of contact of the mixture with the catalyst while the αCO2/α acid ratio is not affected. The study of two alcohols deuterated either in OH group (C2H5OD) or in the alkyl group ((C2D5OH) has shown that the substitution of C-H for C-D bond enhances the stability of the primary oxidation product, deuterated ethanal, so that it is not transformed further to acetic acid.

System for the Automated Mitigation of Hypergolic Propellant Leaks

2012 ◽  
Author(s):  
Alton Reich
Keyword(s):  
High Reliability ◽  
Automated System ◽  
Explosion Hazard ◽  
Vapor Pressures ◽  
Propulsion Systems ◽  
Ignition System ◽  
Rocket Propellants ◽  
High Vapor ◽  
Liquid Rocket ◽  
Design And Testing

Hypergolic liquid rocket propellants consist of fuel and oxidizer liquids stored in separate tanks that ignite when mixed. They are favored for propulsion systems where precise pulsing or throttling is required. High reliability is also insured because the liquid chemicals are stable for long periods of time, and no ignition system is required — the fuel and oxidizer simply need to be brought together. These propellants have relatively high vapor pressures, are toxic, and may be carcinogenic. A pool of the liquid will pose a health, fire, or explosion hazard. Therefore, missiles containing these propellants are stored and shipped in canisters that contain a sensor to detect the leakage of these propellants that will sound an alarm at a set concentration. This paper discusses the development of an automated system that is designed to mitigate a leak of the fuel or oxidizer within the canister in order to render the system safe enough to allow access to the missile. The mitigation system neutralizes the leaked propellant. The design and testing of the system with representative propellants is discussed.

Studies on the rearrangement of (trichloromethyl)carbinols to α-chloroacetic acids

1980 ◽  
Vol 58 (5) ◽  
pp. 485-493 ◽  
Author(s):  
Wilkins Reeve ◽  
James R. McKee ◽  
Robert Brown ◽  
Sitarama Lakshmanan ◽  
Gertrude A. McKee
Keyword(s):  
Carbon Monoxide ◽  
Potassium Hydroxide ◽  
Potential Importance ◽  
Chloroacetic Acids ◽  
Aqueous Potassium Hydroxide ◽  
Mechanism Of The Reaction

Phenyl(trichloromethyl)carbinol undergoes an unimolecular, predominantly intramolecular conversion into potassium α-chlorophenylacetate on stirring with 10 % aqueous potassium hydroxide at 0 °C for several days. Besides providing an interesting example of a 1–2 chlorine shift, the reaction is of potential importance for the synthesis of α-chloro acids. The study of a variety of (trichloromethyl)carbinols shows the reaction is general for secondary (trichloromethyl)carbinols as well as trichloroethanol. The mechanism of the reaction involves the preliminary formation of an epoxide. Several mechanisms are considered for the conversion of the epoxide to the α-chloroacetate anion, but none accounts for all of the experimental facts. Tertiary carbinols break down at the epoxide stage into a ketone and carbon monoxide.

Reactions of tert-Butyl Peroxy Esters, XIV. Further Observations on the Preparation of Dialkyl tert-Butylperoxy Phosphates

1975 ◽  
Vol 30 (9-10) ◽  
pp. 732-739 ◽  
Author(s):  
G. Sosnovsky ◽  
E. H. Zaret
Keyword(s):  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Sodium Hydride ◽  
High Yield ◽  
Butyl Hydroperoxide ◽  
Tert Butyl ◽  
Tert Butyl Hydroperoxide ◽  
Aqueous Potassium Hydroxide ◽  
Butyl Peroxide

The preparation of dialkyl tert-butylperoxy phosphates (2, R = alkyl) has been achieved by the reaction of the corresponding dialkyl phosphorochloridates (1, R = alkyl) with tert-butyl hydroperoxide either in the presence of pyridine or in the presence of aqueous potassium hydroxide solution. Neither of these routes is suitable for the preparation of dialkyl tert-butylperoxy phosphates in quantity since they yield peroxyphosphates which are contaminated either with the corresponding tetraalkyl pyrophosphates or dialkyl phosphates; the contaminants cannot easily be removed by conventional means from the peroxyphosphates. The method of choice for the preparation in high yield of large quantities of pure dialkyl tert-butylperoxy phosphates involves the interaction of the corresponding dialkyl phosphorochloridate with sodium tert-butyl peroxide which has been prepared in situ from the reaction of tert-butyl hydroperoxide with sodium hydride.

THE PHASE TEST INTERMEDIATE AND THE ALLOMERIZATION OF CHLOROPHYLL a

1958 ◽  
Vol 36 (1) ◽  
pp. 439-456 ◽  
Author(s):  
A. S. Holt
Keyword(s):  
Chlorophyll A ◽  
Absorption Spectra ◽  
Potassium Permanganate ◽  
Infrared Absorption ◽  
Potassium Hydroxide ◽  
Dimethyl Ester ◽  
Alcoholic Solution ◽  
Pheophorbide A ◽  
Aqueous Potassium Hydroxide ◽  
Infrared Absorption Spectra

The phase test intermediate of methyl chlorophyllide a is generated in organic solvents by alkoxyl and hydroxyl ions. The intermediate is oxidized by oxygen and such oxidants as iodine, p-benzoquinone, and potassium permanganate. Different products are obtained depending on the solvent, the base used to generate the intermediate, and the oxidant. Three fractions are obtained from methanol containing oxygen and traces of magnesium methoxide. These are (1) Mg-purpurin 7-trimethyl ester, (2) Mg-purpurin 7-lactone-methyl ether-dimethyl ester, and (3) Mg-10-oxy-methyl pheophorbide a. The first and third fractions each make up 10–15% of the total oxidized pigment. Mg-"unstable" chlorin diester is obtained by oxidation with potassium permanganate of the phase test intermediate generated in pyridine by aqueous potassium hydroxide. Mg-10-methoxy-methyl pheophorbide a is obtained by oxidation with iodine of the phase test intermediate generated in methanol by magnesium methoxide (ca. 7%, w/v). It is concluded that allomerization of chlorophyll in alcoholic solution is due to oxidation by oxygen of traces of phase test intermediate.The visible and infrared absorption spectra of the allomerized derivatives are presented and discussed.

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