CHED 813 |
Electrocyclic ring opening of bicyclo[4.2.0]oct-7-ene
| Sarah S. Gallagher1, P. A. Leber1, and John E. Baldwin2. (1) Department of Chemistry, Franklin & Marshall College, P. O. Box 3003, Lancaster, PA 17604-3003, (2) Department of Chemistry, Syracuse University, Syracuse, NY 13244 |
A properly labeled bicyclo[4.2.0]oct-7-ene is an experimental probe of the degree of orbital symmetry control in the electrocyclic reaction of bicyclo[4.2.0]oct-7-ene to 1,3-cyclooctadiene. We have prepared two bicyclo[4.2.0]oct-7-enes from labeled and unlabeled cyclohexene using the following synthetic sequence: ketene cycloaddition, NaBH4 reduction, mesylation, and dissolving metal reduction. The NMR analysis of 2,2,5,5-d4-bicyclo[4.2.0]oct-7-ene is consistent with the label being in the designated place. The kH/kD ratio for this thermal reaction will enable us to differentiate between the two mechanisms drawn below.  |
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