3,4-dihydro-2H-pyran → 2-phenyl-1-[4-(tetrahydro-2H-pyran-2-yloxy)phenyl]butan-1-one

Participants

Reaction Conditions

Reaction Steps

A mixture of compound 8 (908 g, 3.78 mol) in 1,2-dichloroethane (6.36 L) stirred at 30° C. was treated with dihydropyran (1590 g, 18.9 mol) in a single portion. The resulting solution was treated with CaCl2 (83.8 g, 0.76 mmol) in a single portion and the reaction warmed at 70° C. for 16 h. The reaction was filtered through celite and the solid washed with 1,2-dichloroethane (2×900 mL). The filtrate was concentrated by distillation to approximately 5 L and heptane added (9 L). The reaction solution was again concentrated by distillation to approximately 7 L and then cooled slowly and held at 5° C. for 1 h. The solids were filtered, washed with heptane (2×1.8 L) and dried in vacuo at 40° C. to afford 1134 g (93%) of 9 as a solid. 1HNMR (400 MHz, DMSO-d6): δ 0.79 (t, J=7.3 Hz, 3H), 1.49-1.83 (m, 8H), 2.03 (h, J=7.0 Hz, 1H), 3.49-3.66 (m, 2H), 4.65 (t, J=7.2 Hz, 1H), 7.02 (d, J=8.4 Hz, 2H), 7.13-7.30 (m, 5H), 7.97 (d, J=8.4 Hz, 2H).

Provenance & Evidence