Water → HCID 59511065, compound

Participants

Reaction Steps

Neat 23 (1.48 g, 12.65 mmol) was dissolved in CH2Cl2 (127 mL) and treated with a catalytic amount of p-toluene sulfonic acid monohydrate (0.048 g, 20 μmol) and (trimethoxymethyl)benzene (3.26 mL, 18.98 mmol) in CH2Cl2 at room temperature for 1 hr. After the formation of the orthoester was complete, a stoichiometric amount of water (340 μL, 18.98 mmol) was added to the mixture. The mixture was then stirred for 40 min and concentrated in vacuo. Purification of the residue by silica gel flash chromatography using 25% EtOAc/hexanes gave 2.6 g of monoacylated product 27 (93% yield) as a clear, colorless oil. 1H NMR (CDCl3, 400 MHz) δ: 8.03-8.06 (m, 2H), 7.58 (tt, J=1.6, 2.0, 1.6 1H), 7.43-7.47 (m, 2H), 4.54 (dd, J=4.4, 12.0 Hz, 1H), 4.46 (dd, J=6.8, 12.0 Hz, 1H), 3.85-3.91 (m, 1H), 3.80 (dd, J=4.8, 11.6 Hz, 1H), 3.73 (dd, J=6.0, 11.6 Hz, 1H).

Provenance & Evidence