Tetrabutylammonium Fluoride (ca. 1mol/L in Tetrahydrofuran)

Used Chemicals

• 5-O-tert-Butyldiphenylsilyl-2,3-O-isopropylidene-D-ribono-1,4-lactone
• TBAF (ca. 1mol/L in Tetrahydrofuran) [T1338]
• THF

Procedure

To a mixture of 5-O-tert-butyldiphenylsilyl-2,3-O-isopropylidene-D-ribono-1,4-lactone (100 mg, 0.234 mmol) in THF (100 mL) was cooled with an ice/water bath. TBAF (ca. 1 mol/L in THF, 0.3652 mL, 0.352 mmol) was added dropwise to the mixture and stirred at the same temperature for 2 h. sat. NH₄Cl aq. (10 mL) and ethyl acetate (25 mL) were added to the reaction mixture and the two layers were separated. The organic layer was washed with water (10 mL), sat. NaCl aq. (10 mL), dried over Na₂SO₄ and concentrated under reduced pressure. The residue was triturated in hexane (5 mL) to give 2,3-O-isopropylidene-D-ribonic γ-lactone (0.0389 g, 88% yield) as a white solid.

Experimenter’s Comments

The reaction mixture was monitored by TLC (dichloromethane:ethyl acetate = 9:1, Rf = 0.5, stained by KMnO₄ solution containing K₂CO₃ and NaOH).

Analytical Data

¹H NMR (400 MHz, CDCl₃); δ 4.82(d, 1H, J = 5.6 Hz), 4.76 (d, 1H, J = 5.6 Hz), 4.61 (t, 1H, J = 2.0 Hz), 4.00 – 3.95 (1H, m), 3.83 - 3.78 (1H, m), 1.88 (1H, t, J = 5.2 Hz), 1.47 (3H, s), 1.37 (3H, s).

Other Reference

• Novel Deprotection of SEM Ethers:  A Very Mild and Selective Method Using Magnesium Bromide
• A. Vakalopoulos, H. M. R. Hoffmann, Org. Lett. 2000, 2, 1447.

Reference

• A New and Efficient Hypervalent Iodine-Benzyne Precursor, (Phenyl)[o-(trimethylsilyl)phenyl]iodonium Triflate: Generation, Trapping Reaction, and Nature of Benzyne
  • T. Kitamura, M. Yamane, K. Inoue, M. Todaka, N. Fukatsu, Z. Meng, Y. Fujiwara, J. Am. Chem. Soc. 1999, 121, 11674.

References

• New approach to synthesize β,β-difluorohomoallylic alcohols
• M. Omote, T. Miake, A. Tarui, K. Sato, I. Kumadaki, A. Ando, J. Fluorine Chem. 2013, 147, 1.