Methyl iodide → alpha-Irone

Participants

Reaction Conditions

Reaction Steps

A solution of 50.0 g (0.26 mol) of α-ionone in 150 ml of ether were allowed to drop over a period of 20 minutes into a Grignard solution, which was cooled to 0° C. and which had been prepared from 7.5 g (0.31 mol) of magnesium shavings in 75 ml of ether and 46.9 g (0.33 mol) of methyl iodide in 180 ml of ether, in such a manner that the temperature lay between 10° C. and 20° C. Subsequently, the mixture was stirred at the reflux temperature of the ether for a further 1 hour, cooled down to 0° C. and then cautiously treated with concentrated ammonium chloride solution and an additional 500 ml of ether. The ether phase was washed with water until neutral, dried and concentrated. There were obtained 60.0 g of crude product which contained above 95% 9-methyl-α-ionol (GC) and which was accordingly further processed directly in this form. In a manner analogous to the epoxidation of α-irone (Example 4), from 58.1 g (~0.26 mol) of 9-methyl-α-ionol there were obtained 68.0 g of crude 9-methyl-α-ionol epoxide.

Provenance & Evidence