Dimethyl acetylenedicarboxylate → 4,5-Bis(trimethylsilyloxy)cyclohexa-1,4-diene-1,2-dicarboxylic acid dimethyl ester

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Reaction Steps

Under argon, a solution of 7.1 g (50 mmol) of acetylenedicarboxylic acid dimethyl ester in 30 ml of toluene is added dropwise to 12.5 g (50 mmol) of 2,3-bis(trimethylsilyloxy)-1,3-butadiene (95%) and then boiled under reflux for 19 hours. The reaction mixture is cooled, the solvent is evaporated off and the residue is distilled under a high vacuum (0.1 mbar, 124°-127°), yielding the title compound in the form of a yellow, highly viscous oil, 1H-NMR (CDCl3): δ=0.18 (s, 18H), 3.09 (s, 4H), 3.78 (s, 6H).

Provenance & Evidence