dimethyl 2-(2-methylbuta-2,3-dienyl)-2-(prop-2-ynyl)malonate 在
N-甲基吲哚酮 、
dicobalt octacarbonyl 作用下,
生成 3a-Methyl-4-methylene-5-oxo-3,3a,4,5-tetrahydro-1H-pentalene-2,2-dicarboxylic acid dimethyl ester 、 7-Methyl-2-oxo-1,2,4,6-tetrahydro-indene-5,5-dicarboxylic acid dimethyl ester