“…The crude product was purified by flash chromatography (SiO 2 ; n-hexanes) affording pure compound 7 as a colorless oil; yield: 1.21 g (90%). 1 96, 137.42, 135.77, 135.39, 134.56, 128.43, 127.50, 123.08, 121.69, 115.16, 114.20, 68.09, 37.42, 31.82, 31.47, 29.90, 29.58, 29.55, 29.51, 29.26, 26.73, 22.59, 14. 8A solution of 6 (1.029 g, 2 mmol) in anhyd THF (60 mL) under N 2 atmosphere was cooled to -78 °C. After 15 min, a 1.0 M THF/hexane solution of LDA (0.471 g, 4.400 mmol) was added dropwise and the reaction mixture was kept for 2 h at the same temperature.…”