Dimethyl Sulfoxide → (2E,6E)-3,7,11-trimethyldodeca-2,6,10-trienal

Participants

Reaction Steps

To a stirred solution of 2.5 ml (28.7 mmol) of distilled oxalyl chloride in 50 ml of dry CH2Cl2 at -60° C. was added 4.2 ml (58.5 mmol) of DMSO in 10 ml of CH2Cl2 over 6 minutes between -60° and -55° C. with much gas evolution. After 7 minutes at -60° C., a solution of 5.0 g (22.50 mmol) of E,E-farnesol in 14 ml of CH2Cl2 was added over 15 minutes to give a thick white suspension. After 20 minutes at -65° C., 19 ml (136 mmol) of triethylamine was added over 7 minutes and 5 minutes later the cold bath was removed and the reaction was allowed to warm to room temperature over 50 minutes. The mixture was diluted with 400 ml of ether, washed with two 50 ml portions each of water and brine, dried over MgSO4, and evaporated. The residue was taken up in ether, filtered to remove some insoluble solid, and evaporated to provide 5.06 g (100%) of crude E,E-farnesal, contaminated with a trace of the 2Z-isomer.

Provenance & Evidence