反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: A 0° C. solution of 4-(3-bromophenyl)-3,6-dihydro-2H-pyran (0.50 g, 2.09 mmol) in CH2Cl2 (15 mL) is treated with paraformaldehyde (0.208 g, 2.20 mmol) and stirred for 5 minutes at 0° C. A 1 M solution of dimethylaluminum chloride in hexanes (3.03 mL, 3.03 mmol) is added drop-wise to the slurry. The reaction is warmed to room temperature and stirred for 1 hour. The reaction is cooled to 0° C. and more paraformaldehyde (0.208 g, 2.20 mmol) and 1 M solution of dimethylaluminum chloride in hexanes (3.03 mL, 3.03 mmol) is added. The reaction is warmed to room temperature and stirred overnight. The reaction is quenched by pouring into an ice/1 N HCl mixture and is extracted three times with EtOAc. The combined organic layers are dried over Na2SO4 and the solvent is removed under reduced pressure to afford a residue that is purified on silica gel chromatography eluting with a linear gradient of 5% to 100% EtOAc in hexanes to give the title compound (0.315 g, 53%). 1H NMR (400 MHz, CDCl3) δ 7.50 (t, J=2.0 Hz, 1H), 7.40 (dd, J=2.2, 7.9 Hz, 1H), 7.29-7.27 (m, 1H), 7.20 (t, J=7.9 Hz, 1H), 6.11 (t, J=2.9 Hz, 1H), 4.32-4.29 (m, 2H), 4.28-4.25 (m, 1H), 3.76 (dd, J=3.1, 11.4 Hz, 1H), 3.70-3.64 (m, 2H), 2.70 (d, J=2.2 Hz, 1H), 1.89 (dd, J=4.6, 6.4 Hz, 1H).
The reaction is warmed to room temperature
stirred for 1 hour
The reaction is cooled to 0° C.
The reaction is warmed to room temperature
stirred overnight
The reaction is quenched
by pouring into an ice/1 N HCl mixture
is extracted three times with EtOAc
The combined organic layers are dried over Na2SO4
the solvent is removed under reduced pressure
to afford a residue that
is purified on silica gel chromatography
eluting with a linear gradient of 5% to 100% EtOAc in hexanes
来源 ID: ord-8c97b1bc25de4d63843c6ccabe5575b8