Triethylamine (25.2 ml, 0.18 mol) was added dropwise to a cooled (0° C.) solution of diethyl phosphite (23.2 ml, 0.18 mol) and product of Example 4 (50.0 g, 0.17 mol) in carbon tetrachloride (100 ml). The reaction mixture, which had developed a heavy flocculent precipitate, was stirred at 0° C. for 30 minutes before being warmed to room temperature for an additional 24 hours. The reaction mixture was washed consecutively with 1N aq hydrochloric acid (1×250 ml), 0.5N aqueous sodium hydroxide (4×100 ml) and water (1×250 ml) before being dried (MgSO4), filtered and evaporated (aspirator) to a yellow oil (61.53 g). Kugelrohr distillation (120° C. at 25 Pa) afforded the product as a very pale yellow oil (59.03 g). Yield-82%, nD25 1.4197.
