1-ethynyl-2-methyl penten-2-ol, also known as 2-Methyl-1-acetylenyl-2-pentene-1-ol, is a derivative of acetylene and 2-methyl-2-pentenal. Molecular formula: C8H12O, molecular weight: 124.18.
1-ethynyl-2-methyl penten-2-ol is a colorless and oily liquid with a reduced pressure boiling point of 112–115°C at 10 kPa. It is insoluble in water but soluble in organic
solvents such as ethers and alcohols.
1-ethynyl-2-methyl penten-2-ol is a pesticide intermediate that can be used for
manufacture of insecticides such as empenthrin and chlorempenthrin. These pyrethroids are repellents for mosquitoes, flies, cockroaches and clothing pests.
Acetylene reacts with 2-methyl-2-pentenal to produce 1-ethynyl-2-methyl penten-2-ol: