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The Birch reduction is an organic reaction that is used to convert arenes to 1,4-cyclohexadienes.The reaction is named after the Australian chemist Arthur Birch and involves the organic reduction of aromatic rings in an amine solvent (traditionally liquid ammonia) with an alkali metal (traditionally sodium) and a proton source (traditionally an alcohol).
Cyclohexenone is obtained by Birch reduction of anisole followed by acid hydrolysis. It can be obtained from cyclohexanone by α-bromination followed by treatment with base. Hydrolysis of 3-chloro cyclohexene followed by oxidation of the cyclohexenol is yet another route.
Solvated electrons are involved in the reaction of alkali metals with water, even though the solvated electron has only a fleeting existence. [10] Below pH = 9.6 the hydrated electron reacts with the hydronium ion giving atomic hydrogen, which in turn can react with the hydrated electron giving hydroxide ion and usual molecular hydrogen H 2. [11]
Anisole, or methoxybenzene, is an organic compound with the formula CH 3 OC 6 H 5. It is a colorless liquid with a smell reminiscent of anise seed, and in fact many of its derivatives are found in natural and artificial fragrances .
Lawesson's reagent is commercially available. It can also be conveniently prepared in the laboratory by heating a mixture of anisole with phosphorus pentasulfide until the mixture is clear and no more hydrogen sulfide is formed, [2] then recrystallized from toluene or xylene. Samples give a strong odor of hydrogen sulfide owing to partial ...
Arthur John Birch, AC CMG FRS FAA (3 August 1915 – 8 December 1995) was an Australian organic chemist. [1] [2] [3] [4]Birch developed the Birch reduction of aromatic rings (by treatment with lithium metal and ammonia) which is widely used in synthetic organic chemistry.
Their addition allows to decrease the water-to-cement ratio of concrete or mortar without negatively affecting the workability of the mixture. It enables the production of self-consolidating concrete and high-performance concrete. The water–cement ratio is the main factor determining the concrete strength and its durability. Superplasticizers ...
Concrete creep is essentially the sagging of concrete over time. Creep and shrinkage of concrete are two physical properties of concrete.The creep of concrete, which originates from the calcium silicate hydrates (C-S-H) in the hardened Portland cement paste (which is the binder of mineral aggregates), is fundamentally different from the creep of metals and polymers.