19311-37-6Relevant articles and documents
Bromination of alkenols with the H2O2 - LiBr - CeIII and H2O2 - LiBr - CeIV systems
Nikishin,Sokova,Kapustina
, p. 459 - 463 (2012)
Reactions of alkenols with H2O2 - LiBr - Ce(NO 3)3·6H2O or H2O2 - LiBr - Ce(NH4)2(NO3)6 system led to bromination of the double bond to yield vicinal dibromoalkanols. The reaction proceeded highly selectively, no oxidation of the hydroxyl group virtually occurred.
A 3 - halogenated tetrahydrofuran preparation method
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Paragraph 0038; 0039, (2019/05/28)
The invention discloses a 3 - halogenated tetrahydrofuran preparation method. The method comprises the following steps: in the organic solvent, 0 - 85 °C temperature, shown in formula I compound with a reducing agent, can be; wherein R1 And R2 The same, they are selected from chlorine or bromine; the reducing agent is sodium borohydride or potassium borohydride; wherein the organic solvent is b [...], 2 - chloroethyl methyl ether, ethyl ether, tetrahydrofuran or methyl tetrahydrofuran. The method of the invention less reaction steps, the process is simple, the product yield can reach 80% - 95%, and the low cost of raw materials, equipment investment, the price of the product there are advantages; in addition the method pollution is small, friendly to the environment, and is suitable for large-scale industrial production.
Br+ and I+ transfer from the halonium ions of adamantylideneadamantane to acceptor olefins. Halocyclization of 1,ω-alkenols and alkenoic acids proceeds via reversibly formed intermediates
Neverov,Brown
, p. 962 - 968 (2007/10/03)
The kinetics of the transfer of X+ from the bromonium and iodonium ions of adamantylideneadamantane (1-Br+ and 1-I+) to some 1,ω-alkenols and alkenoic acids in ClCH2CH2Cl at 25°C was investigated. In all cases, the expected products of halocyclization were observed. For the iodonium ion transfer the reaction kinetics are second order overall, first order in both 1-I+ and acceptor olefin. Transfer of the bromonium ion from 1-Br+ to these acceptor olefins exhibits different kinetic characteristics. In most cases, the rate of the Br+ transfer is subject to strong retardation in the presence of added parent olefin (Ad=Ad), suggestive of a common species rate depression. In some cases, such as 4-penten-1-ol (2b) and 4-pentenoic acid (4b), the reaction can be completely suppressed at high [Ad=Ad]. In other cases, such as 3-buten-1-ol (2a), 5-hexen-1-ol (2c), cyclohexene, 4-(hydroxymethyl)cyclohexene (3), and 5-endo-carboxynorbornene (5), added Ad=Ad does not suppress the reaction completely. In the cases of the 1,ω-alkenols, the reactions appear to exhibit kinetic terms that are greater than first order in alkenol. In these cases, alcohols such as 1-pentanol also accelerate the reaction, pointing to the involvement of the hydroxyl group of the second alkenol as a catalytic species. A unifying mechanism consistent with the data that involves two reversibly formed intermediates is presented.