Abstract:
2-Methylbut-3-yn-2-ol, a tertiary propargylic alcohol, reacts with acetylene under pressure in superbase KOH/DMSO suspension (80°C, 1h) to afford, along with the expected vinyl ether, 2,2,4,4-tetramethyl-5-methylidene-1,3-dioxolane, 2,5-dimethyl-5-(vinyloxy)hex-3-yn-2-ol and (Z)-2-methyl-4-(2-methylbut-3-yn-2-yloxy)but-3-en-2-ol.