mixture is then stirred for a further 12 hours the reaction mixture is poured over ice and concentrated hydrochloric acid is added thereto to the congo acid reaction the reaction mixture is taken up in ether the solvent removed by distillation and the residue distilled through a 25 cm fractionation column packed with raschig rings the forerun is discarded 4 methyl 2hexenoic acid distills at 118 120 u00b0 10 mmhg n d 20 1 4532 yield 94 225g 232 g of 4 methyl 2hexenoic acid 380 ml of absolute ethanol and 23 g of concentrated sulfuric acid are charged into a 1 liter round bottom flask equipped with condenser the mixture is heated under reflux for 12 hours quenched with 500 ml of water and extracted with ether the ether layer is washed twice with 10 aqueous sodium carbonate solution and with water and the solvent removed by distillation the residue is then distilled through a 25 cm fractionation column packed with raschig rings to yield 4 methyl 2 hexenoic acid ethyl ester b p 76 u00b0 n d 20 1 4376 20 g of 4 methyl 2 hexenoic acid ethyl ester and 25 g of 3 cis hexenol are heated to boiling over 0.