A solution of compound 1 (11.50 g, 0.076 mol) in ethanol (90 ml) was added dropwise to a stirred mixture of compound 7 (15.0 g, 0.069 mol) and tetrakis(triphenylphosphine)palladium(O) (2.38 g, 2.06 mmol) in benzene (130 ml) and 2M-sodium carbonate (100 ml) at room temperature under dry nitrogen. The stirred mixture was heated under reflux (90°-95° C.) for 4.5 h (i.e., until glc analysis revealed absence of starting material). The mixture was cooled and stirred for 1 h at room temperature with 30% hydrogen peroxide (2 ml). The mixture was further cooled to 2° C., and the product was filtered off and washed with water. The product was dried (CaCl2) in vacuo to give fawn-coloured needles.
