Imidazole → 4-(2-iodoethyl)-2,2-dimethyl-1,3-dioxolane

Participants

Reaction Conditions

Reaction Steps

Triphenylphosphine (172 mmol, 45 g) and imidazole (172 mmol, 12 g) were dissolved in THF/acetonitrile (3:1, 300 ml). The mixture was cooled under an ice bath, and iodine (172 mmol, 44 g) was added in four portions with vigorous stirring over 20 minutes. The resulting slurry was warmed to 20° C. and then cooled to 0° C. (±)-2-(2,2-Dimethyl-[1,3]dioxolan-4-yl)-ethanol (156 mmol, 25 g) was added dropwise to the reaction mixture over 15 minutes. The mixture was stirred at room temperature overnight. The mixture was concentrated, diluted with 5% sodium bicarbonate solution and extracted with hexane. The combined organic layer was dried with MgSO4 and concentrated. Silica gel chromatography gave 4-(2-iodo-ethyl)-2,2-dimethyl-[1,3]dioxolane as a clear oil; 1H NMR (400 MHz, CDCl3): δ 4.18-4.12 (m, 1H), 4.06 (dd, 1H, J=8.0 Hz, J2=6.1 Hz), 3.55 (dd, 1H, J1=8.0 Hz, J2=6.5 Hz), 3.28-3.17 (m, 2 H), 2.11-1.98 (m, 2H), 1.38 (s, 3H), 1.33 (s, 3H).

Provenance & Evidence