According to the description in a reference (see: Syn. Lett. 07, 1053–1054, 1999), the title compound was prepared as follows. 12 g (35 mmole) of ethyl 2-{[t-butyl(diphenyl)silyl]oxy}acetate was dissolved in 200 ml of tetrahydrofuran (THF) and 2.2 ml of titaniumtetraisopropoxide was added thereto. To the mixture was slowly added 29.2 ml of ethylmagnesiumbromide (3.0M in THF), and the reaction solution was stirred for 12 hours at room temperature. 20 ml of saturated ammonium chloride was added to stop the reaction. About 150 ml of tetrahydrofuran (THF) used as a solvent was removed by distillation under reduced pressure, and the reaction mixture was extracted twice with 200 ml of ethyl acetate. The ethyl acetate extract was distilled under reduced pressure to give 11.4 g (Yield 100%) of the title compound as a white solid.
