Methanol → 3,7-Dimethyl-2,7-octadienoic acid

Participants

Reaction Steps

To 11.0 mmol of cuprous iodide in 30 ml of dry diethyl ether at -40° under nitrogen is added 10.6 mmol of methyllithium in hexane, followed immediately by 13.0 mmol of tetramethylethylenediamine (TMEDA). After stirring for 30 min, the suspension is cooled to about -50°, and 10 mmol of the methyl ester of 7-methyl-7-octen-2-ynoic acid in 1 ml ether is added dropwise. The temperature is maintained at -45° to -50° for 20 min and then 2 ml of methanol is added dropwise to quench the reaction, followed by 1 ml sat. (NH4)2SO4. The suspension is allowed to warm to RT, after which the solid is filtered off and washed with ether. The combined organic layers are washed with sat. (NH4)2SO4, 5% HCl, sat. NaHCO3 and brine, then dried over CaSO4. The solvent is removed by distillation, yielding the Z methyl ester of 3,7-dimethyl-2,7-octadienoic acid.

Provenance & Evidence