
%0 Journal Article
%A Anthony, IJ 
%A Wege, D 
%T The Synthesis and Reactivity of 5H-Cycloprop[f]isobenzofuran and Related Compounds. A Kinetic Probe for the Mills-Nixon Effect
%J Australian Journal of Chemistry
%D 1996/12/01
%V 49
%N 12
%P 1263-1272
%K 
%R https://doi.org/10.1071/CH9961263
%U https://www.publish.csiro.au/paper/CH9961263 
%X 5H-Cycloprop[f]isobenzofuran (6) and the sulfur analogue 5H-cyclopropa[f][2] benzothiophen (18) have been prepared by a sequence of reactions involving trapping of 1,2-dibromocyclopropene with 3,4-dimethylidenetetrahydrofuran and 3,4-dimethylidenetetrahydrothiophen followed by sequential dehydrogenation and di-dehydrobromination. Both cyclopropa -fused heterocycles, like their parents, have limited stability. Several other 5,6-methylene-bridged and 5,6-disubstituted isobenzofurans (32) have been generated and characterized as their adducts with dimethyl fumarate . Second-order rate constants for the reaction of dimethyl  fumarate with isobenzofuran, 5H-cycloprop[f] isobenzofuran as well as the series of substituted derivatives have been measured. The reactivity span is only one order of magnitude suggesting that &#960;-bond fixation (the Mills-Nixon effect) does not play a significant role in determining the reactivity of (6). 
