6153-05-5

3230-69-1

6153-05-5

The general procedure for the synthesis of (Z)-3-methylpent-3-en-1-yn-5-ol from 3-methyl-1-penten-4-yn-3-ol was as follows: 100.0 g of 3-methyl-1-penten-4-yn-3-ol (a compound of formula (1)) was dissolved in 500.0 g of isopropyl ether, and 20.0 g of catalyst containing 96% of the catalyst was added followed by addition of dilute sulfuric acid (containing 0.1%) and pH was adjusted to 2.0-3.0. The reaction mixture was heated to 34?36°C in a water bath with continuous stirring for 60 min. Upon completion of the reaction, 610.3 g of the organic oil layer solution was obtained by separation using a 1000 ml dispensing funnel, of which (Z)-3-methylpent-3-en-1-yn-5-ol (compound (2)) was determined to be 13.5% by gas phase internal standard method. The above organic oil layer was washed twice with 2 x 150.0 ml saturated NaHCO3 solution, followed by washing with water and vacuum to remove the isopropyl ether, and the concentrate was obtained by neutralization via heat recovery. The concentrate was subjected to reduced pressure distillation via an oil pump and the fractions were collected to give 81.1 g of (Z)-3-methylpent-3-en-1-yn-5-ol (cis (2)), which was determined to be 98.5% pure by gas phase internal standard method. The yield based on the feedstock 3-methyl-1-penten-4-yn-3-ol was 79.8%. The mass of residue (3) was 36.4 g, in which the ratio of raw material 3-methyl-1-penten-4-yn-3-ol to residue (3) was 30.3%.