Acetic Acid → HCID 11378684, compound

Participants

Reaction Conditions

Reaction Steps

183.8 g of (R)-4-ethynyl-3,5,5-trimethyl-3-cyclohexen-1-yl acetate (prepared according to Example 10) were dissolved in 1 l of methanol. The solution was cooled to 0° C. and treated portionwise within 15 minutes with 74.2 g of potassium hydroxide in such a manner that the temperature did not exceed 11° C. The mixture was stirred at 4°-8° C. for a further 15 minutes and then at room temperature for 30 minutes. The reaction mixture was subsequently poured into 2 l of water and 26.5 g of glacial acetic acid. The mixture was extracted three times with 500 ml of methylene chloride each time. The organic phases were washed with 500 ml of saturated sodium chloride solution and with 600 ml of saturated sodium bicarbonate solution, dried over sodium sulphate and filtered. The filtrate was concentrated almost completely in a rotary evaporator under a water-jet vacuum at 30° C. bath temperature. The residual oil was dissolved in 300 ml of pentane and the solution was evaporated completely in a rotary evaporator under a water-jet vacuum at 30° C. bath temperature. The oil obtained was dried at room temperature for 30 minutes in a high vacuum, whereby spontaneous crystallization (strongly exothermic) took place. There were thus obtained 146 g of (R)-4-ethynyl-3,5,5-trimethyl-3-cyclohexen-1-ol (purity 98%, chemical yield 98.8%) as colourless crystals having a pale violet hue; Rf value (diisopropyl ether). 0.40.

Provenance & Evidence