Synthesis of 5-Methylene-1,3-oxazolidin-2-ones

1,4-Dioxane, often just calleddioxane, is a clear, colorless which is a at room and . It has the C4H8O2 and a boiling point of 101°C. It is commonly used as an .1,4-Dioxane has a weak similar to that of . There are also two otherless common compounds, 1,2-dioxane and1,3-dioxane. 1,2-Dioxane is a which forms naturally in old bottlesof .

Synthesis and Application of a New Chiral Auxiliary Derived from (1R,2S)-Norephedrine and Acetone

1,4-Dioxane is highly soluble in groundwater, does not readilybind to soils, and readily leaches to groundwater. It is alsoresistant to naturally occurring biodegradation processes. Due tothese properties, a 1,4-dioxane plume is often much larger (andfurther downgradient) than the associated solvent plume.


Part 1: The Synthesis of (S)-2-Methylhexanoic Acid

A Novel Asymmetric Synthesis of Unsaturated Aromatic 1,2-Amino Alcohols

With colchicine (1) in hand, we proceeded to investigate our proposed syntheses of β-lumicolchicine (3) and NCME (2) (). The irradiation of a 10:1 (v/v) CH3CN/acetone solution of 1 (0.0025 mol/L) with a 125 W high-pressure mercury arc lamp surrounded by a Pyrex water jacket for 25 min resulted in β-lumicolchicine (3) with a much improved yield of 68%.


RU2382774C2 - 2,5-dioxane-1,4-diones synthesis …

D Bernhardt.; H Diekmann. Degradation of dioxane, tetrahydrofuran and other cyclic ethers by an environmental Rhodococcus strain. Applied microbiology and biotechnology. 19913 6 (1), 120-123.

1,4-Dioxane - bromine (1:1) | C4H8Br2O2 | ChemSpider

D Bernhardt.; H Diekmann. Degradation of dioxane, tetrahydrofuran and other cyclic ethers by an environmental Rhodococcus strain. Applied microbiology and biotechnology. 19913 6 (1), 120-123.H Fujioka.; H Kitagawa.; Y Nagatomi.; Y Kita. Asymmetric synthesis using C2-symmetric diols: Use of (5R,6R)-2,3-diacetoxy-5,6-diphenyl-1,4-dioxane as a chiral synthetic equivalent of 1,2-ethanediol 1,2-dicarbocation. Tetrahedron: Asymmetry. 19956 (9), 2113-2116.

Asymmetric synthesis of 1,2-dioxanes: approaches to …

Subsequently, the proposed transition-metal-catalyzed decarbonylation/electrocyclic ring-opening cascade reaction of 3 was attempted using several different catalysts (Rh, Ni, and Pd) in a variety of different solvents, as reported previously. However, these conditions failed to afford any of the desired product of 2. To our delight, the irradiation of a solution of β-lumicolchicine (3) in 10:1 (v/v) CH3CN/acetone (0.0024 mol/L) with a 125 W high-pressure mercury arc lamp surrounded by a Pyrex water jacket for 20 min gave 2 in 54% yield instead of α-lumicolchicine (4) and colchicine. The outcome of this transformation suggested that under the irradiation compound 3 had probably undergone a decarbonylation process to generate the intermediate B, followed by the anticipated retro-4π-electrocyclization reaction to give 2, which has been reported to exhibit greater inhibitory activity toward tubulin than colchicine. The 1H and 13C NMR spectra of synthetic 2 and 3, as well as their optical rotation, were identical to those of the natural products. We also have tried to extend the time of irradiation for one-pot synthesis of compound 2 from 1, but a trace of 2 was detected. Probably, other unidentified compounds made the reaction more complex, with the time extended and the temperature of the solution increased. So, after many attempts, we found that 25 min is the best time length for the first irradiation and the two-step sequence is more efficient than the one-pot procedure for the preparation of 2 from 1.

Patent US4760154 - Synthesis of dioxane - Google …

Retrosynthetically (), β-lumicolchicine (3) could be prepared from colchicine (1) through a 4π-electrocyclization reaction. We anticipate that NCME (2) would be synthesized from 3 through a Rh-catalyzed decarbonylation process via intermediate A to give the fused bicyclobutene B, followed by an electrocyclic ring-opening reaction. The formation of the more stable aromatic ring C is one of the driving forces for this process. It was envisioned that colchicine (1) could be generated from 6 through a Wacker oxidation, followed by the regioselective formation of the tropolone C-ring. Tricyclic 6 could itself be synthesized from 7 through the intramolecular oxidopyrylium-mediated [5 + 2] cycloaddition reaction. Compound 7 could be synthesized from 5 through several simple functional group transformations reported previously.