Propene oxide, rearrangement

Criegee biradicals formed in the reaction of ozone with alkenes carry significant internal excitation and the majority of them decompose before they can be collisionally stabilized. The biradicals are sufficiently excited that many different rearrangements and decomposition pathways are energetically allowed. For example, in the case of the [CH3C( )H00( )] species formed during propene oxidation the IUPAC panel has recommended the following channels (and yields) [24] ... 

Epoxide Rearrangement.- The rearrangement of epoxides in the presence of solid catalysts is strongly dependent on the nature of the catalysts. Propene oxide in the presence of solid catalysts containing acidic conetres, like Si02-Mg0, Mg2(P0 )2 is... 

The addition of BF3-OEt2 to an a-phosphorylated imine results in the 1,3-transfer of a diphenylphosphinoyl group, with resultant migration of the C-N=C triad. This method is less destructive than the thermal rearrangement. The decomposition of dimethyldioxirane in acetone to methyl acetate is accelerated with BF3 OEt2, but acetol is also formed. Propene oxide undergoes polymerization with BF3-OEt2 in most solvents, but isomerizes to propionaldehyde and acetone in dioxane. ... 

Rearrangement of the epoxides to phenols competes with hydration to dihyd-rodiols. The hydration is catalyzed by the microsomal enzyme epoxide hydrolase 362). Dihydrodiols are not formed in the absence of epoxide hydrolase or in the presence of inhibitors of epoxide hydrolase such as l,l,l-trichloro-2,3-propene oxide (TCPO) 138, 203, 417). The dihydrodiols are formed stereospecifically from the 4,5-, 7,8-, and 9,10-epoxides as the (—)-trans isomers 416, 506). 

Ford GP, Smith CT (1987) Gas-phase hydrolysis of protonated oxirane. Ab initio and semiempirical molecular orbital calculations. JAm Chem Soc 109(5) 1325-1331 Coxon JM, Maclagan DGAR, Rauk A, Thorpe AJ, Whalen D (1997) Rearrangement of protonated propene oxide to protonated propanal. J Am Chem Soc 119(20) 4712 718 Korzan R, Upton B, Turnbull K, Seybold PG (2010) Quantum chemical study of the energetics and directionality of acid-catalyzed aromatic epoxide ring openings. Int J Quant Chem 110(15) 2931 2937... 

Arylpropionaldehydes are produced from 1-aryl-1-propene by oxidative rearrangement with iodine and Ag20 in dioxane-H20 (eq 14). The mechanism may involve the 1,2-shift of the aryl group through a bridged phenonium ion in the iodohydrin intermediate. 

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