ACETOLYSES OF 1-SUBSTITUTED TRANS-7,8-DICHLORODIBENZOBICYCLO OCTADIENES.

Article abstract of DOI:10.1016/S0040-4020(01)96064-8

The preparations and silver-assisted acetolyses of the 1-methoxy (5), 1-methyl (6), 1-carbomethoxy (7), and 1-nitro (8) derivatives of trans-7,8-dichlorodibenzobicyclo <2.2.2> octa-2,5-dienes are described.Rearranged products possessing the dibenzobicyclo <3.2.1> octadiene skeleton were identified.With compound 5, the P₈:P₇ ratio (ratio of products derived from ionizations of C₈-Cl and C₇-Cl bonds) was 1.3.For 6 and 7, the corresponding P₈:P₇ ratios were 0.4 and 33 respectively.Acetolysis of 8 led to products in detectable quantities from ionization of the C₈-Cl bond only.The data support the proposal by Cristol that the transition states for these solvolytic rearrangements more closely resemble phenonium ion-like intermediates than benzyl cations.