3-Methyl-1-penten-4-yn-3-ol is an acetylenic alcohol. It reacts with ruthenium vinyl carbene to form a ten-membered η2-olefin coordinated ruthenacycle. The efficiency of different palladium catalysts for the hydrogenation of 3-methyl-1-penten-4-yn-3-ol under continuous-flow liquid-phase conditions has been evaluated. It undergoes allylic rearrangement to form cis and trans isomers of 3-methyl-2-penten-4-yn-l-ol.