To a solution of 4-(1-hydroxy-3-methyl-butyl)-benzoic acid methyl ester (1600 mg, 7.21 mmol) in toluene (72 mL) is added 1,1′-(azodicarbonyl)dipiperidine (ADDP, 2728 mg, 10.81 mmol) at 0° C., followed by the additions of tributylphosphine (2.69 mL, 10.81 mmol) and 4-bromo-3-[1,3]dioxan-2-yl-phenol (2240 mg, 8.65 mmol). The reaction mixture is warmed up to room temperature and stirred overnight. The mixture is loaded on silica gel, eluted with hexanes with a gradient from 0% of ethyl acetate to 50% of ethyl acetate giving the titled compound (1000 mg).
