Abstract Treatment of trimethylsilyl-substituted alkynyl ketones with 1, 2-ethanedithiol in the presence of BF 3· OEt 2 in methanol afforded the corresponding dithioacetal. Removal of the silyl group under basic conditions followed by palladium-catalyzed coupling reactions with aryl iodides yielded the corresponding propargylic dithioacetals in excellent yield.