Carbon Dioxide → HCID 86737708, compound

Participants

Reaction Steps

A solution of 4.7 g (23.0 mmol) of cuprous bromide/dimethyl sulfide complex (prepared as in Example 1C), 20 ml of ether and 42 ml of dimethyl sulfide, under nitrogen, is cooled to about -50°. A 0.41 M solution of 4-methyl-4-penten-1-yl magnesium bromide (51 ml, 21.9 mmol) (prepared as in Example 1B) is added over a 1 hr period. The reaction is stirred approximately 1.5 hr, and then about 4 ml propyne is added and the mixture is warmed to -20°. After 1 hr, 25 ml of HMPA and triethylphosphite are added, followed by excess carbon dioxide. The mixture is warmed to -15° and placed in a CCl4 /CO2 bath, and carbon dioxide is bubbled into the reaction overnight. The reaction is worked up by adding (NH4)2SO4, then filtered. The remaining solid is extracted with ether 4X and filtered. The filtrate (organic and aqueous phases) is salted with NaCl and extracted 3X with ether. The combined ether layers are extracted 3X with NaOH, and the NaOH layers are washed with ether, then acidified with H2SO4. The aqueous layer is salted out (NaCl), extracted with ether, washed with brine and dried over NaSO4 to yield (Z)-3,7-dimethyl-2,7-octadienoic acid.

Provenance & Evidence