PURPOSE: To produce 1,1,3,4,4,6-hexamethyltetralin useful as a synthetic intermediate for musky perfumes in good yield.
CONSTITUTION: An organometallic compound of formula I (M is magnesium chloride or lithium atom) and methyl isopropyl ketone are subjected to the addition reaction in the presence of cerium chloride in an amount of 0.01-0.5mol based on 1mol compound of formula I in a solvent such as an aromatic hydrocarbon or ethers, preferably at -10 to +20°C temperature to provide 2,3,5- trimethyl-3-hydroxy-5-tolylhexane of formula II. The resultant addition reactional solution is then washed with water to remove the solvent. A hydrocarbon solvent is further added to the obtained reactional solution and the prepared solution is subsequently dropped into a suspension of sulfuric acid in a hydrocarbon solvent to carry out the cyclodehydration at 0-100°C, preferably 20-50°C temperature. Thereby, the objective compound of formula III is obtained. The compound of formula I is obtained by reacting 1-chloro-2-methyl-2-tolylpropane with an equivalent magnesium or 2 equivalents lithium.
YONEDA KOICHI
HOSOGAI TAKEO
