Stilbenes reduction kinetics

The product of the reaction with c/s-stilbene was a trichloroacetate ester which yielded the wcso-glycol upon reduction with lithium aluminium hydride the /raHs-olefin yielded the racemic glycol after the same treatment . Such reaction products are consistent with ring-opening of the epoxide by strong acid, and it was shown that (-)-rraHs-stilbene oxide reacted rapidly (relative to the rate of epoxidation) with trichloroacetic acid in benzene the overall observations are indicative of acid-catalysed epoxidation of stilbene but may admit other interpretations, one of which involves thermodynamic intervention of trichloroacetic acid dimer in a solvating capacity rather than in a truly kinetic function. 

An experimental mechanistic study of the MTO-catalyzed, alcohol driven DODH of hydrobenzoin to trans-stilbene was recently reported by Abu-Omar and coworkers (Scheme 21 R=Ph) [41]. Kinetic studies of the catalytic reaction in excess 3-octanol (solvent) at 140°C revealed an inductimi period, a zeroth-order dependence on the glycol and half order behavior in MTO the rate dependence on the alcohol reductant was not determined. The half-order catalyst dependence suggests the involvement of a monomer-dimer equilibrium of Re-complexes. Stoichiometric reactivity experiments with NMR monitoring showed that the MeRe 0(glycolate) intermediate could be... 

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