- Novel ring-opening of epoxides and oxetanes with POCl3 or PCl3 in the presence of DMAP
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Efficient synthesis of chlorohydrins by cleavage of oxiranes and oxetanes using POCl3 or PCl3 in the presence of DMAP (4-N,N-dimethylaminopyridine) has been studied.
- Sartillo-Piscil, Fernando,Quintero, Leticia,Villegas, Clarisa,Santacruz-Juárez, Ericka,Anaya De Parrodi, Cecilia
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- Cyclic Trimerization of Oxetanes
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Conditions for obtaining the optimum yield of the cyclic trimer in the cationic oligomerization of oxetanes have been determined.At moderate dilution (0.05 M) with catalytic quantities of BF3 in CH2Cl2, the yield of the cyclic trimer (1,5,9-trioxacyclododecane) from oxetane could be increased to 50percent at the expense of the cyclic tetramer (1,5,9,13-tetraoxacyclohexadecane), 12percent, and polymer.In contrast, 3,3-dimethyloxetane consumed the BF3 catalyst, which had to be renewed, producing, in a slow reaction, a homologous series of fluorohydrins, together with cyclic oligoethers.The fluorohydrins cyclized if treated with gaseous BF3 before work-up, boosting the isolated yields to 20percent cyclic trimer and 8percent cyclic tetramer.With PF5 in CH2Cl2 the catalyst was stable and the reaction fast, and no fluorohydrins were formed; no cyclic trimer but 73percent cyclic tetramer could be isolated.Other solvents (benzene, CHCl=CCl2, CH2ClCH2Cl), other catalysts (SbF5, AlEt3) and other oxetanes (3-methoxymethyl-3-methyloxetane, 3-halomethyl-3-methyloxetane) were also examined.
- Dale, Johannes,Fredriksen, Siw B.
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