Hydrochloric Acid → 4-Acetoxydioxolane

Participants

Reaction Steps

Compound 5 (200 mg, 1.5 mmol) was dissolved in THF (20 mL). To the solution was added 1N NaOH (2 mL, 2 mmol) and the mixture stirred at room temperature for 2 h. To the mixture was added NaHCO3 (3 mmol, 252 mg) then excess BzCl (1.5 mL) and the mixture was stirred at room temperature for 2 h. EtOAc (50 mL) was added and the pH of the solution was adjusted to 1.5 by addition of 6N HCl. Organic solution was washed with H2O (2×5 mL) and dried (Na2SO4). Solvent was removed and the residue was dissolved in THF (20 mL). To the solution was added pyridine (1.5 mmol, 118 mg) and Pd(OAc)4 (3 mmol, 1.33 g) and the mixture was stirred at room temperature for 16 h. EtOAc (100 mL) was added and the mixture was washed with H2O (3×20 mL). The organic layer was dried (Na2SO4). Solvent was removed and the residue was purified by silica gel column (10% EtOAc/Hexanes) to give compound 7 (38%). 1H-NMR (CDCl3): δ 8.10-7.42 (m, 5H, Bz), 6.44, 6.38 (ddd, J=2.0, 4,4, 4.0 Hz, 1H, 4-H), 5.55, 5.46 (tt, J=3.2, 4.0 Hz, 1H, 2-H), 4.43 (m, 2H, 2-CH2), 4.24 (m, 1H, 5-H), 4.02 m, 1H, 5′-H), 2.11, 1.99 (ss, 3H, Ac).

Provenance & Evidence