To a solution of Ethyl 3-(3-(2,6-dimethylbenzyloxy)phenyl)-3-oxopropanoate (Step A, 5 g, 16.02 mmol) in t-butyl alcohol (50 ml) was added a solution of potassium tert-butoxide (1M in t-butyl alcohol, 1.988 g, 17.7 mmol) and the reaction mixture was stirred for 30 minutes at room temperature. Ethyl 3-bromopropionate was added drop wise to the reaction mixture and stirring continued for another 2 hours and then poured into 1M HCl, extracted with ethyl acetate (2×), washed with brine, dried over Na2SO4, filtered, concentrated and purified by flash chromatography eluted with hexane:ethyl acetate (2:1) to give the title compound.
