ORGN 92 |
| The role of nonstatistical dynamics in carbene chemistry is explored through the reactivity of diacetyl carbene. We have generated this carbene under flash-vacuum pyrolysis conditions, through a retro-Diels Alder reaction by way of an oxirene. The symmetric carbene can insert into adjacent carbon-carbon bonds to form two identical ketene derivatives. These ketenes are distinguishable isotopomers if a carbon-13 label is appropriately incorporated into the carbene precursor. After trapping the ketenes with methanol, analysis shows that the two products are not formed in equal amounts. In other words, a symmetric intermediate can lead to an asymmetric product distribution. These results support the theory that the vibrational energy gained in the formation of an intermediate can affect its subsequent reactivity and thus that a reactive intermediate's reactivity can be dependent on how it is generated. |
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Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry, and High-Energy Species
1:00 PM-5:20 PM, Sunday, 10 September 2006 Moscone Center -- Room 133, Oral
Division of Organic Chemistry |