Abstract α-Lithiated (trimethylsilyloxy) butatrienes, generated by 1, 4-elimination of methanol from 1-trimethylsilyloxy-4-methoxy-2-alkynes with tert-butyllithium, give mixtures of α-allenic aldehydes and allenyl trimethylsilyl ketones which can be separated by distillation. The ratio aldehyde/ketone is solvent dependent.
