Chlorotrimethylsilane → (5R,3S)-5-[(tert-Butyldiphenylsilyl)hydroxymethyl]-dihydro-3-(phenylselenenyl)-2(3H)-furanone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 4 (5 g, 14.1 mmol) in anhydrous THF (50 mL) at −78° C. was added lithium bis(trimethylsilyl)amide (1 M solution in THF, 15.8 mL, 15.8 mmol) over a period of 10 min. After being stirred at −78° C. for 1 h, Me3SiCl (1.918 g, 17.65 mmol) was added dropwise, and the reaction mixture was allowed to warm to room temperature. After being stirred at room temperature for 30 min, the mixture was cooled to −78° C., and a solution of PhSeBr (5 g, 21.19 mmol) in anhydrous THF (25 mL) was added rapidly. The mixture was diluted with ether (50 mL), washed with water until the color of organic layer changed from dark brown to light yellow, dried (Na2SO4), filtered, and evaporated. The resulting oily residue [containing 3S (α, 5) and 3R (β) isomers; TLC: hexane/EtOAc, 10:1; Rf=0.42 and 0.28, respectively] was purified by flash chromatography on silica gel, eluting with hexane/EtOAc (99:1 to 95:5) to give the title compound 5 as a light yellow oil (4.093 g, 57%). 1H NMR (CDCl3) δ 7.69-7.60 (m, 6H, arom.), 7.46-7.30 (m, 9H, arom.), 4.37-4.34 (m, 1H, H-5), 4.12-4.08 (m, 1H, H-3), 3.86-3.82 (dd, J=3 & 11 Hz, 1H, CH2OH), 3.62-3.59 (dd, J=3 & 11 Hz, 1H, CH2OH), 2.73-2.67 (m, 1H, H-4), 2.32-2.28 (m, 1H, H-4), 1.02 (s, 9H, t-Bu).

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