105-29-3

3-Methyl-2-penten-4-yn-1-ol, also known as C6 alcohol or 3-methylpent-2-en-4-yn-1-ol, is a derivative of methyl vinyl ketone and acetylene. (Z)-3-Methyl-2-penten-4-yn-1-ol is a pharmaceutical intermediate for the production of vitamin A. Its stereoisomer, (Z)-3-methyl-2-penten-4-yn-1-ol, is also a useful intermediate for the manufacture of astaxanthin, zeaxanthin and further carotenoids.

3-Methyl-2-penten-4-yn-1-ol has cis and trans isomers. E type: oily liquid, boiling point 165-167℃, relative density 0.922, refractive index 1.4850, flash point 65℃; Z type: oily liquid, boiling point 89-92℃/4kPa, relative density 0.897, refractive index 1.4930, flash point 75 °C. Both isomers are easy to polymerize, and they will explode when heated to above 120°C in a sealed tube.

Used as intermediate of vitamin A acetate.

3-Methyl-2-penten-4-yn-1-ol is synthesized by allyl rearrangement fo methyl vinyl ethynyl methanol at 80°C under moderate acid.