to dryness followed by recrystallization 0 5 moles of n undecyl cyanide and 0 5 moles of diethyl oxalate are mixed in 1 000 ml of dimethylformamide to this solution is added with ice cooling 0 52 moles of potassium t butoxide the mixture is allowed to stir overnight at room temperature following evaporation rotary evaporator under vacuum of most of the dimethylformamide the residue is mixed with 3 liters of diethyl ether followed by the addition of 1 liter water the mixture is acidified with concentrated hydrochloric acid to a ph of 3 and then the ether phase is separated after washing the ether with water and drying the ether over magnesium sulfate evaporation of the ether affords 3 cyano 2 oxotridecanoic acid ethyl ester recrystallization from petroleum ether at 30 u00b0 60 u00b0 c provides pure material 1 g of the 3 cyano 2 oxotridecanoic acid ethyl ester is dissolved in 5 ml of methanesulfonic acid and the mixture allowed to stand overnight at room temperature the reaction mixture is worked up by first pouring into ethanol water 20 ml ethanol 5 ml water after standing for several hours the ethanol is removed by evaporation the aqueous acidic residue is diluted further with water and then extracted with chloroform the chloroform solution is then washed well with water dried and evaporated to give the desired 3 hydroxy 4 n decyl 3 pyrroline 2 5.