In contrast to 1H-indene (1a) and 1-methyl-1H-indene (1b), which give stable 1:2 adducts (3a, 34%; 3b, 30%) and with 1a also a 1:3 adduct (4a; 40% from 1a; 71% from 3a) with dimethyl acetylenedicarboxylate (DMAD), 1,1-dimethyl-1H-indene (1d) and DMAD gave as the only crystalline product a cycloadduct of different structural type, dimethyl 1a,7b-cis-dihydro-1,1-dimethyl-1H-cyclopropa[a]naphthalene-2,3-dicarboxylate (5a, 14%), the structure of which has been confirmed by X-ray crystallography.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Organic Chemistry|
|State||Published - 1981|