In 10 ml of dry tetrahydrofuran was dissolved 1.01 g (2.7 mmol) of the diol (131c). The solution was cooled to -40° C. and 1.52 g (8 mmol) of trichloroacetyl isocyanate was added dropwise. After 5 minutes, the temperature was allowed to increase gradually to room temperature and the mixture was stirred for 1 hour. Then, 2 ml of triethylamine and 4 ml of water were added and the mixture was heated at 50° C. for 3 hours. The reaction mixture was diluted with water and extracted with ethyl acetate. The extract was washed with water, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (5% methanol-ethyl acetate) and recrystallized from ethyl acetate-n-hexane to provide 1.0 g (yield 81%) of Compound I-147 as crystals. mp 152-1530° C.
