According to the description in a reference (see: Syn. Lett. 07, 1053–1054, 1999), the title compound was prepared as follows. 10 g (29 mmole) of ethyl 2-{[t-butyl(diphenyl)silyl]oxy}acetate was dissolved in 100 ml of tetrahydrofuran (THF) and 6.0 ml of titaniumtetraisopropoxide was added thereto. To the mixture was slowly added 37 ml of isobutylmagnesiumbromide (2.0M in THF) at −10° C., and the reaction solution was stirred for 12 hours at room temperature. 50 ml of saturated ammonium chloride was added to stop the reaction. The tetrahydrofuran (THF) used as a solvent was removed by distillation under reduced pressure, and the reaction mixture was extracted twice with 500 ml of n-hexane. The n-hexane extract was distilled under reduced pressure and purified by silica gel column to give 5.0 g of the title compound.
